Using Feide with Client Credentials Flow#

OIDC/OAuth defines many different flows, depending on the use case. One of these flows does not include an authenticated end-user. This is called the Client Credentials flow. This flow allows a client to immediately obtain an access token without involving any end users. This flow is typically used in system to system interactions.

One use for the client credentials flow is in data sharing. You can use the flow to obtain an access_token, and exchange it for a JWT which authorizes access to a third party API.

Registering a client to use with client credentials flow#

Any client can be used with client credentials flow, and no special steps are needed during registration.

Using Client Credentials flow#

Here are some references:

To obtain an access token, the client must send a form POST request (application/x-www-form-urlencoded) to the Feide token endpoint with the body grant_type=client_credentials. The request should be authenticated with basic authentication with the client id and client secret. Feide will issue a token that is not associated with any end-user.

Here is an example curl command to obtain an access token:

export CLIENT_ID=4cc40647-0d56-4de2-9f8f-975ff1ca55a8
export CLIENT_SECRET=b54cbb37-1a75-41bc-8471-c44045d6b0e2

Here is an example of expected output:

"access_token": "9c256322-7c11-4220-93d6-fc5ffad3cb13",
"token_type": "Bearer",
"expires_in": 28799,
"scope": "gk_kdto99 gk_tokenissuer"

Accessing protected APIs#

Notice the scopes for accessing third party APIs. They are all prefixed with gk_. Other scopes are mostly relevant only when a user is authenticated. For example, you may not use the userinfo endpoint with a token obtained through client credentials flow, even if the token has e.g. the profile and email scope.

Accessing a protected third party API using such an access token is no different to using regular access tokens.

GET /foo/bar HTTP/1.1
Authorization: Bearer 9c256322-7c11-4220-93d6-fc5ffad3cb13

Preparing a third party API for clients#

When preparing an API for use with a system client, make sure that you verify whether or not the request is a system request or an authenticated user request.

Requests containing an X-Dataporten-userid header represent an authenticated user, and requests without this header are system requests obtained using client credentials flow.

Depending on the use case, access both from systems and authentication users may or may not be acceptable.