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Gluu OAuth Auth and OAuth PEP#

Overview#

The OAuth Auth and OAuth PEP are used for client authentication and to enforce the presence of OAuth scopes for access to resources protected by the Gateway. OAuth scopes are defined in an external OAuth Authorization Server (AS) -- in most cases the Gluu Server. The Gateway and AS leverage the oxd OAuth middleware service for communication.

There are two plugins for OAuth security.

  1. gluu-oauth-auth: Authenticate client by OAuth Token. The plugin priority is 999.
  2. gluu-oauth-pep: Authorization by OAuth token scopes. The plugin priority is 996.

Note

The higher the priority, the sooner your plugin’s phases will be executed in regard to other plugins’ phases

The plugin supports two types of tokens:

  1. Default Access Token: The plugin will authenticate the token using introspection.
  2. Access Token as JWT: The plugin will authenticate the token using JWT to verify. Currently, the plugin supports three algorithms: RS256, RS384 and RS512.

Configuration#

Plugins can be configured at the Service, Route or Global level. There are several possibilities for plugin configuration with services and routes. For information on plugin precedence, read the Kong docs.

Important

During plugin configuration, the GG UI creates a new OP Client if the oxd ID is left blank. However, if configuring with the Kong Admin API, existing client credentials must be used.

Important

konga.log also shows the curl commands for all API requests to Kong and oxd made by the Konga GUI. This curl command can be used to automate configuration instead of using the web interface.

Service Level#

  1. Add Service

    Follow these step to add Service using GG UI:

  2. Add Route

    Route is recommended to reach at kong proxy. Follow these steps to add route:

    • Click on service name or edit button of above added service
    • Click ROUTES
    • Click the + ADD ROUTE button
    • Fill the form by routing details. Check kong docs for more routing capabilities here.

  3. Add Plugins

    Follow these steps to add plugins:

    • Click SERVICES on the left panel
    • Click on name or edit button
    • Click on Plugins
    • Click on + ADD PLUGIN button
    • You will see Gluu OAuth Auth & PEP title and + icon in pop-up
    • Click here for next step

Route Level#

  1. Add Service

    Follow these step to add Service using GG UI

  2. Add Route

    Follow these steps to add route:

    • Click on service name or edit button of above added service
    • Click ROUTES
    • Click the + ADD ROUTE button
    • Fill the form by routing details. Check kong docs for more routing capabilities here.

  3. Add Plugins

    Follow these steps to add plugins:

    • Click ROUTES on the left panel
    • Click on route id/name or edit button
    • Click on Plugins
    • Click on + ADD PLUGIN button
    • You will see Gluu OAuth Auth & PEP title and + icon in pop-up
    • Click here for next step

Global Plugin#

A global plugin will apply to all services and routes.

Follow these steps to add plugins:

  • Click Plugins on the left panel
  • You will see Gluu OAuth Auth & PEP title and + icon in pop-up
  • Click here for next step

Add Plugin#

You will see Gluu OAuth Auth & PEP title and + icon in a pop-up.

oauth-auth-pep-plugin-add

Clicking on the + icon will bring up the below form. Check here for all the parameter descriptions.

11_path_add_oauth_service

Add Plugin using Kong API#

Note

Use OXD API for client registration.

Configuration for gluu-oauth-auth. Check here for parameter descriptions.

$ curl -X POST \
  http://<kong_hostname>:8001/plugins \
  -H 'Content-Type: application/json' \
  -d '{
  "name": "gluu-oauth-auth",
  "config": { <parameters> },
  "route": { "id": "<kong_route_object_id>" }
}'

Configuration for gluu-oauth-pep. Check here for parameter descriptions.

$ curl -X POST \
  http://<kong_hostname>:8001/plugins \
  -H 'Content-Type: application/json' \
  -d '{
  "name": "gluu-oauth-pep",
  "config": { <parameters> },
  "route": { "id": "<kong_route_object_id>" }
}'

The above example is passing route property which will add the plugin for route level.

Request For
"route": { "id": "<kong_route_object_id>" } Plugin will add for kong route object
"service": { "id": "<kong_service_object_id>" } Plugin will add for kong service object
If you not pass any service or route, it will add globally. Plugin will execute for any routes and services

Parameters#

The following parameters can be used in this plugin's configuration.

Gluu-OAuth-Auth#

field Default Description
op_url The URL of your OP server. Example: https://op.server.com
oxd_url The URL of your oxd server. Example: https://oxd.server.com
oxd_id The ID for an existing client used to introspect the token. If left blank, a new client will be registered dynamically
client_id An existing client ID used to get a protection access token to access the introspection API. Required if an existing oxd ID is provided.
client_secret An existing client secret, used to get a protection access token to access the introspection API. Required if an existing oxd ID is provided.
anonymous 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. This value must refer to the Consumer ID attribute that is internal to Kong, and not its custom_id.
pass_credentials pass It allows to 3 values. pass, hide and phantom_token. Used to operate the authorization header from the upstream service as per configuration. In phantom_token case, the plugin will replace bearer token with new generated JWT(with introspection result) token, so for outside there is bearer token and JWT for internal use.

Gluu-OAuth-PEP#

field Default Description
op_url The URL of your OP server. Example: https://op.server.com
oxd_url The URL of your oxd server. Example: https://oxd.server.com
oxd_id The ID for an existing client used to introspect the token. If left blank, a new client will be registered dynamically
client_id An existing client ID used to get a protection access token to access the introspection API. Required if an existing oxd ID is provided.
client_secret An existing client secret, used to get a protection access token to access the introspection API. Required if an existing oxd ID is provided.
oauth_scope_expression Used to add scope security on an OAuth scope token. Check here for description.
deny_by_default true For paths not protected by OAuth scope expressions. If true, denies unprotected paths.
method_path_tree It is for plugin internal use. We use it for tree-level matching for dynamic paths which registered in uma_scope_expression

Note

GG UI can create a dynamic client. However, if the Kong Admin API is used for plugin configuration, it requires an existing client using the oxd API, then passing the client's credentials to the Gluu-OAuth-PEP plugin.

Phantom Token#

In some cases, there is a requirement that bearer token for outside of the network and JWT token for the internal network. Check here for more details.

OAuth Scope Expression#

It is stringify json, providing security for OAuth scopes. It checks the scope (from token introspection) of the token with the configured OAuth expression. Below is the structure of the oauth_scope_expression.

  • path: it is your url which you want to protect. There is a regular expression facility for path configuration. Check here for more dynamic path registration details.
    • condition: it is the array of conditions for the path where you can define acr values to the path. You can add multiple conditions with different Http Method.
      • httpMethods: it is an HTTP Method. During authentication, the plugin uses it as a filter for the request. ? in the HTTP method allow all the http methods. It should be in a capital case. e.g. GET, POST, PUT.
      • scope_expression: It is the rules to check the values. Check the below example for details.
      • data: It is the data for the scope_expression.

Example of JSON expression 

[
  {
    "path": "/images",
    "conditions": [
      {
        "httpMethods": [
          "GET"
        ],
        "scope_expression": {
          "rule": {
            "and": [
              {
                "var": 0
              },
              {
                "or": [
                  {
                    "var": 1
                  },
                  {
                    "var": 2
                  }
                ]
              }
            ]
          },
          "data": [
            "openid",
            "email",
            "clientinfo"
          ]
        }
      }
    ]
  }
]

JSON expression in string format(stringify json) 

"[{\"path\":\"/images\",\"conditions\":[{\"httpMethods\":[\"GET\"],\"scope_expression\":{\"rule\":{\"and\":[{\"var\":0},{\"or\":[{\"var\":1},{\"var\":2}]}]},\"data\":[\"openid\",\"email\",\"clientinfo\"]}}]}]"

13_oauth_scope_expression

At runtime, the plugin matches the scope expression with token scopes. The inner expression is executed first, matching the scopes from the expression one by one with the requested scope. For each match,true is returned. If a check does not match, it returns false.

Example 1: Token with the ["clientinfo"] scope only.

The values of data will convert into Boolean values. If the token scope matches the expression scope, return true. If not, return false.

["openid","email","clientinfo"] --> [false, false, true]

Check the result using http://jsonlogic.com.

13_oauth_scope_check_1

The result is false, so the request is not allowed.

Example 2: Token with ["openid", "clientinfo"] scopes.

The data value is

["openid","email","clientinfo"] --> [true, false, true]

13_oauth_scope_check_2

The result is true, so the request is allowed.

Dynamic Resource Protection#

There are 3 elements to make more dynamic path registration and protection. Check here for more details.

Usage#

Create Client#

Create a client using the create client consumer section or use the oxd register-site API to create a client.

Create Consumer#

A client credential needs to be associated with an existing Consumer object. To create a Consumer, use the Consumer section.

Create a consumer using the Kong Admin API:

$ curl -X POST \
    http://<kong_hostname>:8001/consumers \
    -H 'Content-Type: application/json' \
    -d '{
   "username": "<kong_consumer_name>",
   "custom_id": "<gluu_client_id>"
  }'

Security & Access Proxy#

To access a proxy upstream API, pass an OAuth token in the authorization header. Generate the OAuth token using OP Client credentials by sending a request to the oxd /get-client-token API.

For example, to access a Kong proxy using an OAuth token:

curl -X GET \
  http://<kong_hostname>:8000/{path matching a configured Route} \
  -H 'Authorization: Bearer <oauth_token>' \

Note

Kong normally provides the 8443 port for https by default, but during the setup script installation, it is changed to 443.

Upstream Headers#

When a client has been authenticated, the plugin will append some headers to the request before proxying it to the upstream service to identify the consumer and the end-user in the code:

  1. X-Consumer-ID, the ID of the Consumer on Kong
  2. X-Consumer-Custom-ID, the custom_id of the Consumer (if set)
  3. X-Consumer-Username, the username of the Consumer (if set)
  4. X-Authenticated-Scope, the comma-separated list of scopes that the end-user has authenticated, if available (only if the consumer is not an 'anonymous' consumer)
  5. X-OAuth-Client-ID, the authenticated client ID (only if the consumer is not an 'anonymous' consumer)
  6. X-OAuth-Expiration, the token expiration time, integer timestamp, measured in the number of seconds since January 1, 1970, UTC, indicating when this token will expire, as defined in JWT RFC7519. It is only returned if the consumer is not set to 'anonymous'.
  7. X-Anonymous-Consumer, will be set to true when authentication fails, and the 'anonymous' consumer is set instead.

This information can be used to implement additional logic. For example, use the X-Consumer-ID value to query the Kong Admin API and retrieve more information about the Consumer.