Auth0 OAuth Tokens for AI Service-to-Service Authentication

Question

Pulumi · Accepted Answer

In the context of service-to-service authentication, OAuth tokens are essential for enabling secure communication between different services without human intervention. Auth0 provides this functionality by issuing access tokens after authenticating a service audience using a Client Credentials Grant flow. The workflow typically involves registering two applications in Auth0: one representing the Service (Client) that will consume the token and another service (API) that will validate the token.

To set up Auth0 OAuth tokens for AI service-to-service authentication using Pulumi, you will need to create a Client and an API in Auth0, configure the Client to request access tokens from the API, and then configure your AI Services with the necessary credentials to authenticate via OAuth.

Below is a simplified Pulumi program in Python that sets up Auth0 clients configured properly for service-to-service authentication:

```python
import pulumi
import pulumi_auth0 as auth0

# Creating an Auth0 client for the consuming service.
client = auth0.Client('service-client',
    # The name of the Auth0 Client (the consuming service).
    name='Service Client',
    # The type of application that this client represents.
    app_type='non_interactive',
    # Grant types define how the client can get Access Tokens. `client_credentials` is for service-to-service.
    grant_types=['client_credentials'],
    # The unique identifier for the API which the client wants access to. Replace with actual identifier.
    client_metadata={
        'audience': 'https://{YOUR_AUTH0_DOMAIN}/api/v2/'
    }
)

# Creating an Auth0 resource server (API) that will validate the tokens.
api = auth0.ResourceServer('service-api',
    # The Audience is used to identify the API.
    identifier='https://{YOUR_AUTH0_DOMAIN}/api/v2/',
    # Scopes define access levels which are used for permission settings. Add scopes as needed.
    scopes=[{
        'description': 'Read data',
        'value': 'read:data'
    },
    {
        'description': 'Write data',
        'value': 'write:data'
    }]
)

# Configuring the Client to use the API's identifier as the audience.
client_grant = auth0.ClientGrant('client-grant',
    # The audience is the identifier of the Resource Server (API).
    audience=api.identifier,
    # The client ID of the consuming client.
    client_id=client.client_id,
    # The scopes that you want the access tokens to have.
    scope=["read:data", "write:data"]
)

# Exporting the Client ID and API ID as outputs to be used in the services configuration.
pulumi.export('service_client_id', client.client_id)
pulumi.export('service_api_id', api.identifier)
```

In this Pulumi program, you are creating two main resources:

1. `auth0.Client`: This is representing the service that will consume the access token. You use the `client_credentials` grant type as this setup is for machine-to-machine authentication. The `client_metadata` should contain the identifier for the API you want the client to access.

2. `auth0.ResourceServer`: This represents the API that will validate the access tokens. The `identifier` functions as the API's audience, which the Auth0 Client will use to get the correct access token.

3. `auth0.ClientGrant`: This configures what scopes will be included in the access tokens. It connects the client and the API by setting the API's audience as the scope for the client's access tokens.

By setting the `audience` to the API's identifier and specifying the correct `scopes`, when your AI service uses this client to authenticate with the Auth0 API, it will receive access tokens that grant access to the intended API scopes.

Finally, the two `pulumi.export` statements make the client ID and API ID available as stack exports, which you can use to configure your services.

Make sure to replace `{YOUR_AUTH0_DOMAIN}` with the domain you have for your Auth0 account, and also adjust the scopes and other configuration as necessary for your particular use case.