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 Microsoft Entra ID OIDC enterprise SSO sign-in experience (user authentication) with .NET Core (Razor Pages) and Logto.

Prerequisites

• A running Logto instance. Check out the introduction page to get started.
• Basic knowledge of .NET Core (Razor Pages).
• A usable Microsoft Entra ID OIDC enterprise SSO account.

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 Traditional web 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.
2. In the opening modal, click the "Traditional web" section or filter all the available "Traditional web" frameworks using the quick filter checkboxes on the left. Click the ".NET Core (Razor Pages)" framework card to start creating your application.
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 .NET Core (Razor Pages) with Logto

tip:

• 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:

Program.cs

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.

Sign-in and sign-out flows

Before we proceed, there are two confusing terms in the .NET Core authentication middleware that we need to clarify:

1. CallbackPath: The URI that Logto will redirect the user back to after the user has signed in (the "redirect URI" in Logto)
2. RedirectUri: The URI that will be redirected to after necessary actions have been taken in the Logto authentication middleware.

The sign-in process can be illustrated as follows:

Similarly, .NET Core also has SignedOutCallbackPath and RedirectUri for the sign-out flow.

For the sake of clarity, we'll refer them as follows:

Term we use	.NET Core term
Logto redirect URI	CallbackPath
Logto post sign-out redirect URI	SignedOutCallbackPath
Application redirect URI	RedirectUri

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.

Configure redirect URIs

note:

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

First, let's configure the Logto redirect URI. Add the following URI to the "Redirect URIs" list in the Logto application details page:

http://localhost:3000/Callback

To configure the Logto post sign-out redirect URI, add the following URI to the "Post sign-out redirect URIs" list in the Logto application details page:

http://localhost:3000/SignedOutCallback

Change the default paths

The Logto redirect URI has a default path of /Callback, and the Logto post sign-out redirect URI has a default path of /SignedOutCallback.

You can leave them as are if there's no special requirement. If you want to change it, you can set the CallbackPath and SignedOutCallbackPath property for LogtoOptions:

Program.cs

builder.Services.AddLogtoAuthentication(options =>
{
  // Other configurations...
  options.CallbackPath = "/Foo";
  options.SignedOutCallbackPath = "/Bar";
});

Remember to update the value in the Logto application details page accordingly.

Implement sign-in/sign-out buttons

First, add the handler methods to your PageModel, for example:

Pages/Index.cshtml.cs

public class IndexModel : PageModel
{
  public async Task OnPostSignInAsync()
  {
    await HttpContext.ChallengeAsync(new AuthenticationProperties
    {
      RedirectUri = "/"
    });
  }

  public async Task OnPostSignOutAsync()
  {
    await HttpContext.SignOutAsync(new AuthenticationProperties
    {
      RedirectUri = "/"
    });
  }
}

Then, add the buttons to your Razor page:

Pages/Index.cshtml

<p>Is authenticated: @User.Identity?.IsAuthenticated</p>
<form method="post">
  @if (User.Identity?.IsAuthenticated == true) {
    <button type="submit" asp-page-handler="SignOut">Sign out</button>
  } else {
    <button type="submit" asp-page-handler="SignIn">Sign in</button>
  }
</form>

It will show the "Sign in" button if the user is not authenticated, and show the "Sign out" button if the user is authenticated.

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 Microsoft Entra ID OIDC enterprise SSO connector

To simplify access management and gain enterprise-level safeguards for your big clients, connect with .NET Core (Razor Pages) as a federated identity provider. The Logto enterprise SSO connector helps you establish this connection in minutes by allowing several parameter inputs.

To add an enterprise SSO connector, simply follow these steps:

1. Navigate to Logto console > Enterprise SSO.

2. Click "Add enterprise connector" button and choose your SSO provider type. Choose from prebuilt connectors for Microsoft Entra ID (Azure AD), Google Workspace, and Okta, or create a custom SSO connection using the standard OpenID Connect (OIDC) or SAML protocol.
3. Provide a unique name (e.g., SSO sign-in for Acme Company).

4. Configure the connection with your IdP in the "Connection" tab. Check the guides above for each connector types.

5. Customize the SSO experience and enterprise’s email domain in the "Experience" tab. Users sign in with the SSO-enabled email domain will be redirected to SSO authentication.

6. Save changes.

Set up Azure AD SSO application

Step 1: Create an Microsoft EntraID OIDC application

1. Go to the Microsoft Entra admin center and sign in as an administrator.

2. Browse to Identity > Applications > App registrations.

3. Select New registration.

4. Enter the application name and select the appropriate account type for your application.

5. Select Web as the application platform.

6. Copy and paste the redirect URI from Logto's SSO settings page. The redirect URI is the URL where the user is redirected after they have authenticated with Microsoft Entra ID.

6. Click Register to create the application.

Step 2: Configure Microsoft Entra ID OIDC SSO at Logto

After successfully creating an Microsoft Entra OIDC application, you will need to provide the IdP configurations back to Logto. Navigate to the Connection tab at Logto Console, and fill in the following configurations:

1. Client ID: A unique identifier assigned to your OIDC application by the Microsoft Entra. This identifier is used by Logto to identify and authenticate the application during the OIDC flow. You can find it in the application overview page as Application (client) ID.

2. Client Secret: Create a new client secret and copy the value to Logto. This secret is used to authenticate the OIDC application and secure the communication between Logto and the IdP.

3. Issuer: The issuer URL, a unique identifier for the IdP, specifying the location where the OIDC identity provider can be found. It is a crucial part of the OIDC configuration as it helps Logto discover the necessary endpoints.

   Instead of manually provide all these OIDC endpoints, Logto fetch all the required configurations and IdP endpoints automatically. This is done by utilizing the issuer url you provided and making a call to the IdP's discover endpoint.

   To get the issuer URL, you can find it in the Endpoints section of the application overview page.

   Locate the OpenID Connect metadata document endpoint and copy the URL WITHOUT the trailing path .well-known/openid-configuration. This is because Logto will automatically append the .well-known/openid-configuration to the issuer URL when fetching the OIDC configurations.

4. Scope (Optional): Logto automatically includes the required scopes (openid, profile, and email) in all requests. You can specify additional scopes as a space-separated list if your application requires extra permissions or access levels from the IdP.

Click Save to finish the configuration process

Step 3: Additional scopes (Optional)

Scopes define the permissions your app requests from users and control which data your app can access from their Microsoft Entra ID accounts. Requesting Microsoft Graph permissions requires configuration on both sides:

In Microsoft Entra admin center:

1. Navigate to Microsoft Entra ID > App registrations and select your application.
2. Go to API permissions > Add a permission > Microsoft Graph > Delegated permissions.
3. Select only the permissions your app requires:
   • OpenID permissions:
     • openid (Required) - Sign users in
     • profile (Required) - View users' basic profile
     • email (Required) - View users' email address
     • offline_access (Optional) - Required only if you enable Store tokens for persistent API access in the Logto connector and need to obtain refresh tokens for long-lived access to Microsoft Graph APIs.
   • API access (Optional): Add any additional permissions needed for your app. Common Microsoft Graph permissions include Mail.Read, Calendars.Read, Files.Read, etc. Browse the Microsoft Graph permissions reference to find available permissions.
4. Click Add permissions to confirm the selection.
5. If your app requires admin consent for certain permissions, click Grant admin consent for [Your Organization].

In Logto Microsoft Entra ID connector:

1. Logto automatically includes openid, profile, and email scopes to retrieve basic user identity information. You can leave the Scopes field blank if you only need basic user information.
2. Add offline_access to the Scopes field if you plan to store tokens for persistent API access. This scope enables refresh tokens for long-lived API access.
3. Add additional scopes (separated by spaces) in the Scopes field to request more data from Microsoft Graph. Use standard scope names, for example: User.Read Mail.Read Calendars.Read

tip:

If your app requests these scopes to access the Microsoft Graph API and perform actions, make sure to enable Store tokens for persistent API access in Logto Microsoft Entra ID connector. See the next section for details.

Step 4: Store tokens to access Microsoft APIs (Optional)

If you want to access Microsoft Graph APIs and perform actions with user authorization, Logto needs to get specific API scopes and store tokens.

1. Add the required scopes in your Microsoft Entra admin center API permissions configuration and Logto Microsoft Entra ID connector.
2. Enable Store tokens for persistent API access in Logto Microsoft Entra ID connector. Logto will securely store Microsoft access and refresh tokens in the Secret Vault.
3. To ensure refresh tokens are returned, add the offline_access scope to your Microsoft Entra ID application permissions and include it in your Logto Microsoft Entra ID connector scopes. This scope allows your application to maintain access to resources for extended periods.

Step 5: Set email domains and enable the SSO connector

Provide the email domains of your organization on the connector experience tab. This will enable the SSO connector as an authentication method for those users.

Users with email addresses in the specified domains will be exclusively limited to use your SSO connector as their only authentication method.

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 Microsoft Entra ID OIDC enterprise SSO connector should be available now.

Enable Microsoft Entra ID OIDC enterprise SSO connector in Sign-in Experience

You don’t need to configure enterprise connectors individually, Logto simplifies SSO integration into your applications with just one click.

1. Navigate to: Console > Sign-in experience > Sign-up and sign-in.
2. Enable the "Enterprise SSO" toggle.
3. Save changes.

Once enabled, a "Single Sign-On" button will appear on your sign-in page. Enterprise users with SSO-enabled email domains can access your services using their enterprise identity providers (IdPs).

To learn more about the SSO user experience, including SP-initiated SSO and IdP-initiated SSO, refer to User flows: Enterprise SSO.

Testing and Validation

Return to your .NET Core (Razor Pages) app. You should now be able to sign in with Microsoft Entra ID OIDC enterprise SSO. 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.