Single Sign-On with Okta

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 Okta 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 35 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

  • An Okta administrator account with privileges to create and manage applications.

  • An NGINX Plus subscription and NGINX Plus Release 35 or later. For installation instructions, see Installing NGINX Plus.

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

Configure Okta

In Okta, register a new application for NGINX Plus as the OIDC client to obtain the Client ID, Client Secret, and required OIDC endpoints.

  1. Log in to your Okta admin console.

  2. In the Admin Console, go to Applications > Applications.

  3. Select Create App Integration.

  4. In Create a new app integration, select:

    • Sign-in method: OIDC - OpenID Connect.

    • Application type: Web Application.

    • Select Next.

  5. In New Web App Integration:

    • Enter the Name for your new application, for example, Nginx Demo App.

    • Add a URI for the OIDC callback in Sign-in redirect URIs, for example, https://demo.example.com/oidc_callback.

    • Add a URI for post logout redirect in Sign-out redirect URIs, for example, https://demo.example.com/post_logout/.

    • Select Save.

  6. In Applications, select Nginx Demo App.

  7. In the General tab:

    • Copy the Client ID. You will need it later when configuring NGINX Plus.

    • Copy the Client secret. You will need it later when configuring NGINX Plus.

  8. In the Sign On tab:

    • Copy the Okta Issuer (Authorization Server), for example:

      https://dev-123456.oktapreview.com/oauth2/default

      You will need it later when configuring NGINX Plus.

Get the OpenID Connect Discovery URL

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

https://<okta-domain>/oauth2/default/.well-known/openid-configuration.

  1. Run the following curl command in a terminal:

    curl https://dev-123456.okta.com/oauth2/default/.well-known/openid-configuration | jq

    where:

    • the dev-123456.okta.com is your Okta domain

    • the /oauth2/default is the default authorization server

    • the /.well-known/openid-configuration is the default address for Okta 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:

    {
    ...
    "issuer": "https://dev-123456.okta.com/oauth2/default",
    "authorization_endpoint": "https://dev-123456.okta.com/oauth2/default/v1/authorize",
    "token_endpoint": "https://dev-123456.okta.com/oauth2/default/v1/token",
    "jwks_uri": "https://dev-123456.okta.com/oauth2/default/v1/keys",
    "userinfo_endpoint": "https://dev-123456.okta.com/oauth2/default/v1/userinfo",
    "end_session_endpoint": "https://dev-123456.okta.com/oauth2/default/v1/logout",
    ...
}

  2. Copy the issuer value, you will need it later when configuring NGINX Plus. Typically, the OpenID Connect Issuer for Okta is https://<okta-domain>/oauth2/default.

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

Assign Users or Groups

By default, Okta might limit application access to certain users or groups. To add or remove users in Okta:

  1. Log in to your Okta admin console.

  2. In Applications, choose Nginx Demo App.

  3. Go to Assignments.

  4. Add or remove users and groups that can access this application.

Set up NGINX Plus

With Okta 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:

    nginx -v

    The output should match NGINX Plus Release 35 or later:

    nginx version: nginx/1.29.0 (nginx-plus-r35)

  2. Ensure that you have the values of the Client ID, Client Secret, and Issuer obtained during Okta 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:

    http {
    resolver 10.0.0.1 ipv4=on valid=300s;

    # ...
}

  5. In the http {} context, define the Okta provider named okta by specifying the oidc_provider {} context:

    http {
    resolver 10.0.0.1 ipv4=on valid=300s;

    oidc_provider okta {

        # ...

    }
    # ...
}

  6. In the oidc_provider {} context, specify:

    • your actual Okta Client ID obtained in Okta Configuration with the client_id directive

    • your Client Secret obtained in Okta Configuration with the client_secret directive

    • the Issuer URL obtained in Okta Configuration with the issuer directive

      The issuer is typically your Okta OIDC URL:

      https://dev-123456.okta.com/oauth2/default.

    • 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 Okta should redirect the user after a successful logout. This value must also be configured in the Okta application’s Sign-out redirect URIs.

    • If the logout_token_hint directive set to on, NGINX Plus sends the user’s ID token as a hint to Okta. This directive is optional, however, if it is omitted the Okta may display an extra confirmation page asking the user to approve the logout request.

    • If the userinfo directive is set to on, NGINX Plus will fetch /oauth2/default/v1/userinfo from the Okta and append the claims from userinfo to the $oidc_claims_ variables.

    • 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.

    http {
    resolver 10.0.0.1 ipv4=on valid=300s;

    oidc_provider okta {
        issuer            https://dev-123456.okta.com/oauth2/default;
        client_id         <client_id>;
        client_secret     <client_secret>;
        logout_uri        /logout;
        post_logout_uri   https://demo.example.com/post_logout/;
        logout_token_hint on;
        userinfo          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:

    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 Okta OIDC by specifying the auth_oidc directive that will point to the okta configuration specified in the oidc_provider {} context in Step 5:

    # ...
location / {
     auth_oidc okta;

     # ...

     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 Okta:

    # ...
location / {
     auth_oidc okta;

     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:

    # ...
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:

    # ...
server {
    listen 8080;

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

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

    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;

    # Define the OIDC provider block for Okta
    oidc_provider okta {
        # The 'issuer' is your Okta issuer URL
        # For okta dev it looks like: https://dev-123456.okta.com/oauth2/default
        issuer https://dev-123456.okta.com/oauth2/default;

        # Your Okta "Client ID" from the application settings
        client_id <your_client_id>;

        # Your Okta "Client Secret" from the application settings
        client_secret <your_client_secret>;

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

        # Fetch userinfo claims
        userinfo 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 / {
            # Enforce OIDC authentication with Okta
            auth_oidc okta;

            # Pass OIDC claims as HTTP headers to the backend
            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\nOkta 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 Okta sign-in page.

  2. Enter valid Okta credentials of a user who has access the application. Upon successful sign-in, Okta 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; Okta 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 Okta 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.

Legacy njs-based Okta Solution

If you are running NGINX Plus R33 and earlier or if you still need the njs-based solution, refer to the Legacy njs-based Okta Guide for details. The solution uses the nginx-openid-connect GitHub repository and NGINX JavaScript files.

See Also

Revision History

  • Version 2 (August 2025) – 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)