Single Sign-On with Amazon Cognito

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 Amazon Cognito 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 34 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 AWS account
A Cognito User Pool
An NGINX Plus subscription and NGINX Plus Release 34 or later. For installation instructions, see Installing NGINX Plus.
A domain name pointing to your NGINX Plus instance, for example, demo.example.com.

Configure Amazon Cognito

Open the Amazon Cognito console in the AWS Management Console
In the Cognito dashboard, select Create or open a User Pool.
Create an App Client (for example, “nginx-demo-app”) and enable the “Generate client secret” option.
In the App client settings, select Enable Cognito User Pool as an Identity Provider:
- Add a Callback URL: https://demo.example.com/oidc_callback.
- Enable Authorization code grant.
- In the OAuth scopes, check the values of openid, profile, and email.
Copy the following values — you will need them later when configuring NGINX Plus.
- User Pool ID, for example, us-east-2_abCdEfGhI
- App client id and App client secret
- AWS region, for example, us-east-2
- Issuer, for example, https://cognito-idp.<region>.amazonaws.com/<User Pool ID>

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

Set up NGINX Plus

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

Ensure that you are using the latest version of NGINX Plus by running the nginx -v command in a terminal:
nginx -v
```
nginx -v
```
The output should match NGINX Plus Release 34 or later:
nginx version: nginx/1.27.4 (nginx-plus-r34)
```
nginx version: nginx/1.27.4 (nginx-plus-r34)
```
Ensure that you have the values of the Client ID, Client Secret, and Issuer obtained during Cognito Configuration.
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).
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:
nginx
http { resolver 10.0.0.1 ipv4=on valid=300s; # ... }
```
http {
    resolver 10.0.0.1 ipv4=on valid=300s;

    # ...
}
```

In the http {} context, define the Amazon Cognito provider named cognito by specifying the oidc_provider {} context:

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

    oidc_provider cognito {

        # ...

    }
    # ...
}

In the oidc_provider {} context, specify:
- your actual Amazon Cognito Client ID obtained in Amazon Cognito Configuration with the client_id directive
- your Client Secret obtained in Amazon Cognito Configuration with the client_secret directive
- the Issuer URL obtained in Amazon Cognito Configuration with the issuer directive
  
  The issuer is typically your Amazon Cognito OIDC URL. As a rule, Cognito uses a unique issuer for each User Pool, for example:
  
  https://cognito-idp.us-east-2.amazonaws.com/us-east-2_abCdEfGhI
  
  By default, NGINX Plus creates the metadata URL by appending the /.well-known/openid-configuration part to the Issuer URL. If your Issuer is different, you can explicitly specify the metadata document with the config_url directive.
- 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.
nginx
http { resolver 10.0.0.1 ipv4=on valid=300s; oidc_provider cognito { issuer https://cognito-idp.us-east-2.amazonaws.com/us-east-2_abCdEfGhI; client_id <client_id>; client_secret <client_secret>; } # ... }
```
http {
    resolver 10.0.0.1 ipv4=on valid=300s;

    oidc_provider cognito {
        issuer        https://cognito-idp.us-east-2.amazonaws.com/us-east-2_abCdEfGhI;
        client_id     <client_id>;
        client_secret <client_secret>;
    }

    # ...
}
```

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;
        }
    }
    # ...
}

Protect this location with Amazon Cognito OIDC by specifying the auth_oidc directive that will point to the cognito configuration specified in the oidc_provider {} context in Step 5:

# ...
location / {
     auth_oidc cognito;

     # ...

     proxy_pass http://127.0.0.1:8080;
}
# ...

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 Amazon Cognito:

$oidc_claim_sub - a unique Subject identifier assigned for each user by Amazon Cognito
$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

# ...
location / {
     auth_oidc cognito;

     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;
}
# ...

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\nSub: $http_sub\n";
        default_type text/plain;
    }
}

Save the NGINX configuration file and reload the configuration:
nginx -s reload
```
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 cognito {
        # Typically your Cognito issuer is something like:
        # https://cognito-idp.<region>.amazonaws.com/<UserPoolID>
        issuer https://cognito-idp.us-east-2.amazonaws.com/us-east-2_abCdEfGhI;

        # Your Cognito "App client id" and "App client secret"
        client_id <client_id>;
        client_secret <client_secret>;
    }

    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 path with Cognito OIDC
            auth_oidc cognito;

            # 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;
        }
    }

    server {
        listen 8080;

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

Testing

Open https://demo.example.com/ in a browser. You will be automatically redirected to Amazon Cognito login page for your realm.
Enter valid Cognito user credentials (those in the assigned user pool). Upon successful sign-in, Cognito redirects you back to NGINX Plus, and you will see the proxied application content (for example, “Hello, Jane Doe!”).

Legacy njs-based Amazon Cognito 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 Cognito Guide for details. The solution uses the nginx-openid-connect GitHub repository and NGINX JavaScript files.

Revision History

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

Last modified April 1, 2025