OAuth 2.0 Introspection plugin

Validate access tokens sent by developers using a third-party OAuth 2.0 Authorization Server, by leveraging its Introspection Endpoint (RFC 7662). This plugin assumes that the Consumer already has an access token that will be validated against a third-party OAuth 2.0 server.

Configuration Reference

Enable the plugin on a service

Admin API

Kubernetes

Declarative (YAML)

Kong Manager

For example, configure this plugin on a service by making the following request:

curl -X POST http://{HOST}:8001/services/{SERVICE}/plugins \
    --data "name=oauth2-introspection"  \
    --data "config.consumer_by=username"

SERVICE is the id or name of the service that this plugin configuration will target.

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <oauth2-introspection-example>
config: 
  consumer_by: username
plugin: oauth2-introspection

Next, apply the KongPlugin resource to a Service by annotating the Service as follows:

apiVersion: v1
kind: Service
metadata:
  name: {SERVICE}
  labels:
    app: {SERVICE}
  annotations:
    konghq.com/plugins: <oauth2-introspection-example>
spec:
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
    name: {SERVICE}
  selector:
    app: {SERVICE}

{SERVICE} is the id or name of the service that this plugin configuration will target.

Note: The KongPlugin resource only needs to be defined once and can be applied to any service, consumer, or route in the namespace. If you want the plugin to be available cluster-wide, create the resource as a KongClusterPlugin instead of KongPlugin.

For example, configure this plugin on a service by adding this section to your declarative configuration file:

plugins:
- name: oauth2-introspection
  service: {SERVICE}
  config: 
    consumer_by: username

SERVICE is the id or name of the service that this plugin configuration will target.

Configure this plugin on a service:

In Kong Manager, select the workspace.
From the Dashboard, scroll down to Services and click View for the service row.
Scroll down to plugins and click Add Plugin.
Find and select the OAuth 2.0 Introspection plugin.

Note: If the plugin is greyed out, then it is not available for your product tier. See Kong Gateway tiers.
If the option is available, select Scoped.
Add the service name and ID to the Service field if it is not already prefilled.
Click Create.

Enable the plugin on a route

Admin API

Kubernetes

Declarative (YAML)

Kong Manager

For example, configure this plugin on a route with:

$ curl -X POST http://{HOST}:8001/routes/{ROUTE}/plugins \
    --data "name=oauth2-introspection"  \
    --data "config.consumer_by=username"

ROUTE is the id or name of the route that this plugin configuration will target.

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <oauth2-introspection-example>
config: 
  consumer_by: username
plugin: oauth2-introspection

Then, apply it to an ingress (Route or Routes) by annotating the ingress as follows:

apiVersion: networking/v1beta1
kind: Ingress
metadata:
  name: {ROUTE}
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/plugins: <oauth2-introspection-example>
spec:
  rules:
  - host: examplehostname.com
    http:
      paths:
      - path: /bar
        backend:
          serviceName: echo
          servicePort: 80

ROUTE is the id or name of the route that this plugin configuration will target.

For example, configure this plugin on a route by adding this section to your declarative configuration file:

plugins:
- name: oauth2-introspection
  route: <route>
  config: 
    consumer_by: username

ROUTE is the id or name of the route that this plugin configuration will target.

Configure this plugin on a route:

In Kong Manager, select the workspace.
From the Dashboard, select Routes in the left navigation.
Click View for the route row.
Scroll down to plugins and click Add Plugin.
Find and select the OAuth 2.0 Introspection plugin.

Note: If the plugin is greyed out, then it is not available for your product tier. See Kong Gateway tiers.
If the option is available, select Scoped.
Add the Route ID if it is not already prefilled.
Click Create.

Enable the plugin globally

A plugin which is not associated to any service, route, or consumer is considered global, and will be run on every request. Read the Plugin Reference and the Plugin Precedence sections for more information.

Admin API

Kubernetes

Declarative (YAML)

Kong Manager

For example, configure this plugin globally with:

$ curl -X POST http://{HOST}:8001/plugins/ \
    --data "name=oauth2-introspection"  \
    --data "config.consumer_by=username"

Create a KongClusterPlugin resource and label it as global:

apiVersion: configuration.konghq.com/v1
kind: KongClusterPlugin
metadata:
  name: <global-oauth2-introspection>
  annotations:
    kubernetes.io/ingress.class: kong
  labels:
    global: \"true\"
config: 
  consumer_by: username
plugin: oauth2-introspection

For example, configure this plugin using the plugins: entry in the declarative configuration file:

plugins:
- name: oauth2-introspection
  config: 
    consumer_by: username

Configure this plugin globally:

In Kong Manager, select the workspace.
From the Dashboard, select Plugins in the left navigation.
Click New Plugin.
Find and select the OAuth 2.0 Introspection plugin.

Note: If the plugin is greyed out, then it is not available for your product tier. See Kong Gateway tiers.
If the option is available, set the plugin scope to Global.
Click Create.

Parameters

Here's a list of all the parameters which can be used in this plugin's configuration:

Form Parameter	Description
`name` required Type: string	The name of the plugin, in this case `oauth2-introspection`.
`service.id` Type: string	The ID of the Service the plugin targets.
`route.id` Type: string	The ID of the Route the plugin targets.
`enabled` required Type: boolean Default value: `true`	Whether this plugin will be applied.
`api_id` Type: string	The ID of the API the plugin targets. Note: The API Entity is deprecated in favor of Services since CE 0.13.0 and EE 0.32.
`config.introspection_url`	The full URL to the third-party introspection endpoint
`config.authorization_value`	The value to append to the Authorization header when requesting the introspection endpoint
`config.token_type_hint` optional	The token_type_hint value to associate to introspection requests
`config.ttl` optional Default value: `60`	The TTL in seconds for the introspection response - set to 0 to disable the expiration
`config.hide_credentials` optional	An optional boolean value telling the plugin to hide the credential to the upstream API server. It will be removed by Kong before proxying the request.
`config.timeout` optional Default value: `10000`	An optional timeout in milliseconds when sending data to the upstream server
`config.keepalive` optional Default value: `60000`	An optional value in milliseconds that defines for how long an idle connection will live before being closed
`config.anonymous` optional	An optional string (consumer uuid) value to use as an “anonymous” consumer if authentication fails. If empty (default), the request will fail with an authentication failure 4xx.
`config.run_on_preflight` optional Default value: `true`	A boolean value that indicates whether the plugin should run (and try to authenticate) on `OPTIONS` preflight requests. If set to `false` then `OPTIONS` requests will always be allowed.
`config.consumer_by` optional Default value: `username`	A string indicating whether to associate oauth2 `username` or `client_id` with the consumer’s username. Oauth2 `username` is mapped to a consumer’s `username` field, while an oauth2 `client_id` maps to a consumer’s `custom_id`
`config.introspect_request` optional Default value: `false`	A boolean indicating whether to forward information about the current downstream request to the introspect endpoint. If true, headers `X-Request-Path` and `X-Request-Http-Method` will be inserted in the introspect request
`config.custom_introspection_headers` optional	A list of custom headers to be added in the introspection request
`config.custom_claims_forward` optional	A list of custom claims to be forwarded from the introspection response to the upstream request. Claims are forwarded in headers with prefix `X-Credential-{claim-name}`

Flow

OAuth2 Introspection Flow

Associate the response to a Consumer

To associate the introspection response resolution to a Kong Consumer, you will have to provision a Kong Consumer with the same username returned by the Introspection Endpoint response.

Upstream Headers

When a client has been authenticated, the plugin will append some headers to the request before proxying it to the upstream API/Microservice, so that you can identify the consumer in your code:

X-Consumer-ID, the ID of the Consumer on Kong (if matched)
X-Consumer-Custom-ID, the custom_id of the Consumer (if matched and if existing)
X-Consumer-Username, the username of the Consumer (if matched and if existing)
X-Anonymous-Consumer, will be set to true when authentication failed, and the ‘anonymous’ consumer was set instead.
X-Credential-Scope, as returned by the Introspection response (if any)
X-Credential-Client-ID, as returned by the Introspection response (if any)
X-Credential-Username, as returned by the Introspection response (if any)
X-Credential-Token-Type, as returned by the Introspection response (if any)
X-Credential-Exp, as returned by the Introspection response (if any)
X-Credential-Iat, as returned by the Introspection response (if any)
X-Credential-Nbf, as returned by the Introspection response (if any)
X-Credential-Sub, as returned by the Introspection response (if any)
X-Credential-Aud, as returned by the Introspection response (if any)
X-Credential-Iss, as returned by the Introspection response (if any)
X-Credential-Jti, as returned by the Introspection response (if any)

Additionally, any claims specified in config.custom_claims_forward will also be forwarded with the X-Credential- prefix.

Note: Aforementioned X-Credential-* headers are not set when authentication failed, and the ‘anonymous’ consumer was set instead.

About this Plugin
Plugin Version	0.36-x
Made by	Kong Inc.
Categories	Authentication
Konnect Cloud compatible?	See latest plugin version
Version Compatibility
Kong Gateway 0.36-x 0.35-x 0.34-x