keycloak-scim/topics/service/authorization/authorization-api-aapi.adoc

== Requesting Authorization Data and Token

Client applications using the UMA protocol can use a specific endpoint to obtain a special security token called *Requesting Party Token* or *RPT*.
This token consists of all the permissions granted to an user as a result of the evaluation of the permissions and authorization policies associated with the resource(s) being requested.
With an RPT in hands, client applications can gain access to protected resources at the resource server.

```bash
http://${host}:${port}/auth/realms/${realm_name}/authz/authorize
```

When asking for a RPT, you need to provide two main things:

* A link:../protection/permission-api-papi.adoc[Permission Ticket] with the resources you want to access
* The link:./whatis-obtain-aat.adoc[AAT] (as a bearer token) representing user's identity and his consent to access authorization data on his behalf.

```bash
curl -X POST
    -H "Authorization: Bearer ${AAT}" -d '{
    "ticket" : ${PERMISSION_TICKET}
}' "http://localhost:8080/auth/realms/hello-world-authz/authz/authorize"
```

As a result, you will get the following response from the server:

```json
{"rpt":"${RPT}"}
```

=== Requesting Party Token or RPT

A RPT is basically a https://tools.ietf.org/html/rfc7519[JSON Web Token (JWT)] digitally signed using https://www.rfc-editor.org/rfc/rfc7515.txt[JSON Web Signature (JWS)].
The token is built based on the AAT sent by the client during the authorization process.

When you decode a RPT you will see something like that:

```json
{
  "authorization": {
      "permissions": [
        {
          "resource_set_id": "d2fe9843-6462-4bfc-baba-b5787bb6e0e7",
          "resource_set_name": "Hello World Resource"
        }
      ]
  },
  "jti": "d6109a09-78fd-4998-bf89-95730dfd0892-1464906679405",
  "exp": 1464906971,
  "nbf": 0,
  "iat": 1464906671,
  "sub": "f1888f4d-5172-4359-be0c-af338505d86c",
  "typ": "kc_ett",
  "azp": "hello-world-authz-service"
}
```

From this token you can obtain all permissions granted by the server from the *permissions* claim.