Single Sign-On with Microsoft Entra ID

This guide explains how to enable single sign-on (SSO) for applications being proxied by F5 NGINX Plus. The solution uses OpenID Connect as the authentication mechanism, with Microsoft Entra ID as the Identity Provider (IdP), and NGINX Plus as the Relying Party, or OIDC client application that verifies user identity.

This guide applies to NGINX Plus Release 36 and later. In earlier versions, NGINX Plus relied on an njs-based solution, which required NGINX JavaScript files, key-value stores, and advanced OpenID Connect logic. In the latest NGINX Plus version, the new OpenID Connect module simplifies this process to just a few directives.

Prerequisites

• A Microsoft Entra tenant with admin access.

• Azure CLI. For installation instructions, see How to install the Azure CLI.

• An NGINX Plus subscription and NGINX Plus Release 36 or later. For installation instructions, see Installing NGINX Plus.

• A domain name pointing to your NGINX Plus instance, for example, demo.example.com.

Configure Entra ID

Register a new application in Microsoft Entra ID that will represent NGINX Plus as an OIDC client. This is necessary to obtain unique identifiers and secrets for OIDC, as well as to specify where Azure should return tokens. Ensure you have access to the Azure Portal with Entra ID app administrator privileges.

Register new Azure Web Application

1. Log in to Azure CLI:

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   az login

   This command will open your default browser for authentication.

2. Register a New Application.

   • Create a new application, for example, "Nginx Demo App", with NGINX callback URI /oidc_callback:

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     az ad app create --display-name "Nginx Demo App" --web-redirect-uris "https://demo.example.com/oidc_callback"

   • From the command output, copy the appId value which represents your Client ID. You will need it later when configuring NGINX Plus.

3. Generate a new Client Secret.

   • Create a client secret for your application by running:

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     az ad app credential reset --id <appId>

   • Replace the <appId> with the value obtained in the previous step.

   • From the command output, copy the the password value which represents your Client Secret. You will need it later when configuring NGINX Plus. Make sure to securely save the generated client secret, as it will not be displayed again.

   • From the same command output, copy the the tenant value which represents your Tenant ID. You will need it later when configuring NGINX Plus.

4. Configure logout URLs to support RP-initiated and front-channel logout:

   • Add a logout URL for your application by running:

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     az ad app update --id <appId> --web-logout-urls "https://demo.example.com/post_logout/"

   • Replace the <appId> with the value obtained in step 2.

   • To enable OpenID Connect front-channel logout (single sign-out when the user signs out of another application), configure the Front-channel logout URL for your application in the Microsoft Entra admin center. Set it to the absolute HTTPS URL that matches the frontchannel_logout_uri you will configure in NGINX Plus, for example https://demo.example.com/front_logout.

     According to the OpenID Connect front-channel logout specification, the Identity Provider sends both the issuer (iss) and the session identifier (sid) as query parameters. Microsoft Entra ID currently sends only the sid value; the NGINX Plus OIDC module for NGINX Plus Release 36 supports both the fully compliant (iss + sid) and the Entra-specific (sid‑only) variants and will clear the corresponding user session in either case.

Get the OpenID Connect Discovery URL

Check the OpenID Connect Discovery URL. By default, Microsoft Entra ID publishes the .well-known/openid-configuration document at the following address:

https://login.microsoftonline.com/<tenant_id>/v2.0/.well-known/openid-configuration.

1. Run the following curl command in a terminal:

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   curl https://login.microsoftonline.com/<tenant_id>/v2.0/.well-known/openid-configuration | jq

   Where:

   • the <tenant_id> is your Microsoft Entra Tenant ID

   • the login.microsoftonline.com is your Microsoft Entra server address

   • the /v2.0/.well-known/openid-configuration is the default address for Microsoft Entra ID for document location

   • the jq command (optional) is used to format the JSON output for easier reading and requires the jq JSON processor to be installed.

   The configuration metadata is returned in the JSON format:

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   {
       ...
       "issuer": "https://login.microsoftonline.com/{tenant_id}/v2.0",
       "authorization_endpoint": "https://login.microsoftonline.com/{tenant_id}/oauth2/v2.0/authorize",
       "token_endpoint": "https://login.microsoftonline.com/{tenant_id}/oauth2/v2.0/token",
       "jwks_uri": "https://login.microsoftonline.com/{tenant_id}/discovery/v2.0/keys",
       "userinfo_endpoint": "https://graph.microsoft.com/oidc/userinfo",
       "end_session_endpoint": "https://login.microsoftonline.com/{tenant_id}/oauth2/v2.0/logout",
       ...
   }

2. Copy the issuer value, you will need it later when configuring NGINX Plus. Typically, the OpenID Connect Issuer for Microsoft Entra ID is https://login.microsoftonline.com/<tenant_id>/v2.0.

You will need the values of Client ID, Client Secret, and Tenant ID in the next steps.

Set up NGINX Plus

With Microsoft Entra ID configured, you can enable OIDC on NGINX Plus. NGINX Plus serves as the Rely Party (RP) application — a client service that verifies user identity.

1. Ensure that you are using the latest version of NGINX Plus by running the nginx -v command in a terminal:

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   nginx -v

   The output should match NGINX Plus Release 36 or later:

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   nginx version: nginx/1.29.0 (nginx-plus-r36)

2. Ensure that you have the values of the Client ID, Client Secret, and Tenant ID obtained during Microsoft Entra ID Configuration.

3. In your preferred text editor, open the NGINX configuration file (/etc/nginx/nginx.conf for Linux or /usr/local/etc/nginx/nginx.conf for FreeBSD).

4. In the http {} context, make sure your public DNS resolver is specified with the resolver directive: By default, NGINX Plus re‑resolves DNS records at the frequency specified by time‑to‑live (TTL) in the record, but you can override the TTL value with the valid parameter:

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   http {
       resolver 10.0.0.1 ipv4=on valid=300s;
   
       # ...
   }

5. In the http {} context, define the Entra ID provider named entra by specifying the oidc_provider {} context:

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   http {
       resolver 10.0.0.1 ipv4=on valid=300s;
   
       oidc_provider entra {
   
           # ...
   
       }
       # ...
   }

6. In the oidc_provider {} context, specify:

   • your Client ID obtained in Entra ID Configuration with the client_id directive

   • your Client Secret obtained in Entra ID Configuration with the client_secret directive

   • the Issuer URL obtained in Entra ID Configuration with the issuer directive

     The issuer is typically:

     https://login.microsoftonline.com/<tenant_id>/v2.0.

     By default, NGINX Plus creates the metadata URL by appending the /.well-known/openid-configuration part to the Issuer URL. If your metadata URL is different, you can explicitly specify it with the config_url directive.

   • The logout_uri is URI that a user visits to start an RP‑initiated logout flow.

   • The post_logout_uri is absolute HTTPS URL where Microsoft Entra ID should redirect the user after a successful logout. This value must also be configured in the Entra ID application logout URLs.

   • If the logout_token_hint directive set to on, NGINX Plus sends the user’s ID token as a hint to Microsoft Entra ID. This directive is optional, however, if it is omitted the Microsoft Entra ID may display an extra confirmation page asking the user to approve the logout request. If the “Require ID token in logout requests” option is enabled in your tenant (commonly the case in Azure AD B2C), then the token hint becomes mandatory.

   • The frontchannel_logout_uri directive defines the URI that receives OpenID Connect front-channel logout requests from Microsoft Entra ID. This URI must be an HTTPS path hosted by NGINX Plus and must match the Front-channel logout URL configured in the Entra ID application registration. When a front-channel logout GET request is received at this URI (typically in a hidden iframe), the OIDC module clears the local session for the affected user.

   • If the userinfo directive is set to on, NGINX Plus will fetch userinfo from Microsoft Graph API and append the claims from userinfo to the $oidc_claims_ variables.

   • PKCE (Proof Key for Code Exchange) is automatically enabled when the provider metadata advertises the S256 code challenge method in the code_challenge_methods_supported field of the discovery document. You can override this behavior with the pkce directive: set pkce off; to disable PKCE even when S256 is advertised, or pkce on; to force PKCE even if the IdP metadata does not list S256.

   • The module automatically selects the client authentication method for the token endpoint based on the provider metadata token_endpoint_auth_methods_supported. When only client_secret_post is advertised, NGINX Plus uses the client_secret_post method and sends the client credentials in the POST body. When both client_secret_basic and client_secret_post are present, the module prefers HTTP Basic (client_secret_basic), which remains the default for Microsoft Entra ID.

   • Important

     All interaction with the IdP is secured exclusively over SSL/TLS, so NGINX must trust the certificate presented by the IdP. By default, this trust is validated against your system’s CA bundle (the default CA store for your Linux or FreeBSD distribution). If the IdP’s certificate is not included in the system CA bundle, you can explicitly specify a trusted certificate or chain with the ssl_trusted_certificate directive so that NGINX can validate and trust the IdP’s certificate.

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   http {
       resolver 10.0.0.1 ipv4=on valid=300s;
   
       oidc_provider entra {
           issuer            https://login.microsoftonline.com/<tenant_id>/v2.0;
           client_id         <client_id>;
           client_secret     <client_secret>;
           logout_uri        /logout;
           post_logout_uri   https://demo.example.com/post_logout/;
           logout_token_hint on;
           frontchannel_logout_uri /front_logout;
           userinfo          on;
   
           # Optional: PKCE configuration. By default, PKCE is automatically
           # enabled when the IdP advertises the S256 code challenge method.
           # pkce on;
       }
   
       # ...
   }

7. Make sure you have configured a server that corresponds to demo.example.com, and there is a location that points to your application (see Step 10) at http://127.0.0.1:8080 that is going to be OIDC-protected:

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   http {
   
       # ...
   
       server {
           listen      443 ssl;
           server_name demo.example.com;
   
           ssl_certificate     /etc/ssl/certs/fullchain.pem;
           ssl_certificate_key /etc/ssl/private/key.pem;
   
           location / {
   
               # ...
   
               proxy_pass http://127.0.0.1:8080;
           }
       }
       # ...
   }

8. Protect this location with Entra ID OIDC by specifying the auth_oidc directive that will point to the entra configuration specified in the oidc_provider {} context in Step 5:

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   # ...
   location / {
   
        auth_oidc entra;
   
        # ...
   
        proxy_pass http://127.0.0.1:8080;
   
   }
   # ...

9. Pass the OIDC claims as headers to the application (Step 10) with the proxy_set_header directive. These claims are extracted from the ID token returned by Entra ID:

   • $oidc_claim_sub - a unique Subject identifier assigned for each user by Entra ID

   • $oidc_claim_email - the e-mail address of the user

   • $oidc_claim_name - the full name of the user

   • any other OIDC claim using the $oidc_claim_ variable

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   # ...
   location / {
   
        auth_oidc entra;
   
        proxy_set_header sub   $oidc_claim_sub;
        proxy_set_header email $oidc_claim_email;
        proxy_set_header name  $oidc_claim_name;
   
        proxy_pass http://127.0.0.1:8080;
   }
   # ...

10. Provide endpoint for completing logout:

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    # ...
    location /post_logout/ {
         return 200 "You have been logged out.\n";
         default_type text/plain;
    }
    # ...

11. Create a simple test application referenced by the proxy_pass directive which returns the authenticated user’s full name and email upon successful authentication:

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    # ...
    server {
        listen 8080;
    
        location / {
            return 200 "Hello, $http_name!\nEmail: $http_email\nEntra ID sub: $http_sub\n";
            default_type text/plain;
        }
    }

12. Save the NGINX configuration file and reload the configuration:

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    nginx -s reload

Complete Example

This configuration example summarizes the steps outlined above. It includes only essential settings such as specifying the DNS resolver, defining the OIDC provider, configuring SSL, and proxying requests to an internal server.

http {
    # Use a public DNS resolver for Issuer discovery, etc.
    resolver 10.0.0.1 ipv4=on valid=300s;

    oidc_provider entra {
        # The issuer is typically something like:
        # https://login.microsoftonline.com/<tenant_id>/v2.0
        issuer https://login.microsoftonline.com/<tenant_id>/v2.0;

        # Replace with your actual Entra client_id and client_secret
        client_id <client_id>;
        client_secret <client_secret>;

        # RP‑initiated logout
        logout_uri /logout;
        post_logout_uri https://demo.example.com/post_logout/;
        logout_token_hint on;

        # Front-channel logout (OP‑initiated single sign-out)
        frontchannel_logout_uri /front_logout;

        # Fetch userinfo claims
        userinfo on;

        # Optional: PKCE configuration (enabled automatically when supported by the IdP)
        # pkce on;
    }

    server {
        listen 443 ssl;
        server_name demo.example.com;

        ssl_certificate /etc/ssl/certs/fullchain.pem;
        ssl_certificate_key /etc/ssl/private/key.pem;

        location / {
            # Protect this location with Entra OIDC
            auth_oidc entra;

            # Forward OIDC claims as headers if desired
            proxy_set_header sub $oidc_claim_sub;
            proxy_set_header email $oidc_claim_email;
            proxy_set_header name $oidc_claim_name;

            proxy_pass http://127.0.0.1:8080;
        }

        location /post_logout/ {
            return 200 "You have been logged out.\n";
            default_type text/plain;
        }
    }

    server {
        # Simple test upstream server
        listen 8080;

        location / {
            return 200 "Hello, $http_name!\nEmail: $http_email\nEntra ID sub: $http_sub\n";
            default_type text/plain;
        }
    }
}

Testing

1. Open https://demo.example.com/ in a browser. You will be automatically redirected to the Entra ID sign-in page.

2. Enter valid Entra ID credentials of a user who has access the application. Upon successful sign-in, Entra ID redirects you back to NGINX Plus, and you will see the proxied application content (for example, "Hello, Jane Doe!").

3. Navigate to https://demo.example.com/logout. NGINX Plus initiates an RP‑initiated logout; Microsoft Entra ID ends the session and redirects back to https://demo.example.com/post_logout/.

4. Refresh https://demo.example.com/ again. You should be redirected to Microsoft Entra ID for a fresh sign‑in, proving the session has been terminated.

If you restricted access to a group of users, be sure to select a user who has access to the application.

See Also

• Microsoft identity platform documentation

• NGINX Plus Native OIDC Module Reference documentation

• Release Notes for NGINX Plus R36

Revision History

• Version 3 (November 2025) – Updated for NGINX Plus R36; added front-channel logout support (frontchannel_logout_uri), PKCE configuration (pkce directive), and the client_secret_post token endpoint authentication method.

• Version 2 (August 2025) – Updated for NGINX Plus R35; added RP‑initiated logout (logout_uri, post_logout_uri, logout_token_hint) and userinfo support.

• Version 1 (March 2025) – Initial version (NGINX Plus Release 34).