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# Summary

- [**Name**](#name)
- [**Attributes**](#attributes)
- [**Token Introspection**](#token-introspection)

## Name

The OAuth 2 / Open ID Connect(OIDC) plugin provides authentication and introspection capability to APISIX.

## Attributes

|Name           |Requirement    |Description|
|-------        |-----          |------|
|client_id      |required       |OAuth client ID|
|client_secret  |required       |OAuth client secret|
|discovery      |required       |URL of the discovery endpoint of the identity server|
|realm          |optional       |Realm used for the authentication; default is apisix|
|bearer_only    |optional       |Setting this `true` will check for the authorization header in the request with a bearer token; default is `false`|
|logout_path    |optional       |default is `/logout`|
|redirect_uri   |optional       |default is `ngx.var.request_uri`|
|timeout        |optional       |default is 3 seconds|
|ssl_verify     |optional       |default is `false`|
|introspection_endpoint                 |optional       |URL of the token verification endpoint of the identity server|
|introspection_endpoint_auth_method     |optional       |Authentication method name for token introspection |

### Token Introspection

Token introspection helps to validate a request by verifying the token against an Oauth 2 authorization server.
As prerequisite, you should create a trusted client in the identity server and generate a valid token(JWT) for introspection.
The following image shows an example(successful) flow of the token introspection via the gateway.

![token introspection](../images/plugin/oauth-1.png)

The following is the curl command to enable the plugin to an external service.
This route will protect `https://httpbin.org/get`(echo service) by introspecting the token provided in the header of the request.

```bash
curl http://127.0.0.1:9080/apisix/admin/routes/5 -X PUT -d '
{
  "uri": "/get",
  "plugins": {
    "proxy-rewrite": {
      "scheme": "https"
    },
    "openid-connect": {
      "client_id": "api_six_client_id",
      "client_secret": "client_secret_code",
      "discovery": "full_URL_of_the_discovery_endpoint",
      "introspection_endpoint": "full_URL_of_introspection_endpoint",
      "bearer_only": true,
      "realm": "master",
      "introspection_endpoint_auth_method": "client_secret_basic"
    }
  },
  "upstream": {
    "type": "roundrobin",
    "nodes": {
      "httpbin.org:443": 1
    }
  }
}'
```

The following command can be used to access the new route.

```bash
curl -i -X GET http://127.0.0.1:9080/get -H "Host: httpbin.org" -H "Authorization: Bearer {replace_jwt_token}"
```

## Troubleshooting

Check/modify the DNS settings (`conf/config.yml) if APISIX cannot resolve/connect to the identity provider.