Password grantv1.0+

Configure the OpenID Connect plugin to use the password grant.

This is a legacy authentication grant, as it’s less secure than other flows.

Here’s how the password grant works:

sequenceDiagram
    autonumber
    participant client as Client <br>(e.g. mobile app)
    participant kong as Gateway
    participant idp as IdP <br>(e.g. Keycloak)
    participant httpbin as Upstream <br>(upstream service,<br> e.g. httpbin)
    activate client
    activate kong
    client->>kong: Service with<br>basic authentication
    deactivate client
    kong->>kong: load <br>basic authentication<br>credentials
    activate idp
    kong->>idp: IdP/token with<br>client credentials and<br>password grant
    deactivate kong
    idp->>idp: authenticate client and<br>verify password grant
    activate kong
    idp->>kong: return tokens
    deactivate idp
    kong->>kong: verify tokens
    activate httpbin
    kong->>httpbin: request with access token
    httpbin->>kong: response
    deactivate httpbin
    activate client
    kong->>client: response
    deactivate kong
    deactivate client

In this example, the OpenID Connect plugin will only accept the password sent in a header, but you can also set the config.bearer_token_param_type parameter to body, query, cookie, or any combination of these values.

We’re also passing the client secret in the body of the request. You can pass the secret in more secure ways by using a different config.client_auth option.

For a complete example of authenticating with a username and password pair using Keycloak, see the tutorial for configuring OpenID Connect with the password grant.

Note: Setting config.client_auth to client_secret_post lets you test the connection to your IdP, but we recommend using a more secure auth method in production. You can use any of the supported client auth methods.

Prerequisites

  • A configured identity provider (IdP)

Environment variables

  • ISSUER: The issuer authentication URL for your IdP. For example, if you’re using Keycloak as your IdP, the issuer URL looks like this: http://localhost:8080/realms/example-realm

  • CLIENT_ID: The client ID that the plugin uses when it calls authenticated endpoints of the IdP.

  • CLIENT_SECRET: The client secret needed to connect to your IdP.

  • TOKEN_SALT: A random string that decK requires (v1.59 and later) so session credentials aren’t regenerated on every sync. This parameter is optional for other formats. For example, generate one with openssl rand -base64 16.

Set up the plugin

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