[[_enforcer_claim_information_point]]
= Claim Information Point

A Claim Information Point (CIP) is responsible for resolving claims and pushing these claims to the {project_name} server
in order to provide more information about the access context to policies. They can be defined as a configuration option
to the policy-enforcer in order to resolve claims from different sources, such as:

* HTTP Request (parameters, headers, body, etc)
* External HTTP Service
* Static values defined in configuration
* Any other source by implementing the Claim Information Provider SPI

When pushing claims to the {project_name} server, policies can base decisions not only on who a user is but also by taking
context and contents into account, based on who, what, why, when, where, and which for a given transaction. It is all about
Contextual-based Authorization and how to use runtime information in order to support fine-grained authorization decisions.

== Obtaining information from the HTTP request

Here are several examples showing how you can extract claims from an HTTP request:

.keycloak.json
```json
"policy-enforcer": {
    "paths": [
      {
        "path": "/protected/resource",
        "claim-information-point": {
          "claims": {
            "claim-from-request-parameter": "{request.parameter['a']}",
            "claim-from-header": "{request.header['b']}",
            "claim-from-cookie": "{request.cookie['c']}",
            "claim-from-remoteAddr": "{request.remoteAddr}",
            "claim-from-method": "{request.method}",
            "claim-from-uri": "{request.uri}",
            "claim-from-relativePath": "{request.relativePath}",
            "claim-from-secure": "{request.secure}",
            "claim-from-json-body-object": "{request.body['/a/b/c']}",
            "claim-from-json-body-array": "{request.body['/d/1']}",
            "claim-from-body": "{request.body}",
            "claim-from-static-value": "static value",
            "claim-from-multiple-static-value": ["static", "value"],
            "param-replace-multiple-placeholder": "Test {keycloak.access_token['/custom_claim/0']} and {request.parameter['a']} "
          }
        }
      }
    ]
  }
```

== Obtaining information from an external HTTP service

Here are several examples showing how you can extract claims from an external HTTP Service:

.keycloak.json
```json
"policy-enforcer": {
    "paths": [
      {
        "path": "/protected/resource",
        "claim-information-point": {
          "http": {
            "claims": {
              "claim-a": "/a",
              "claim-d": "/d",
              "claim-d0": "/d/0",
              "claim-d-all": ["/d/0", "/d/1"]
            },
            "url": "http://mycompany/claim-provider",
            "method": "POST",
            "headers": {
              "Content-Type": "application/x-www-form-urlencoded",
              "header-b": ["header-b-value1", "header-b-value2"],
              "Authorization": "Bearer {keycloak.access_token}"
            },
            "parameters": {
              "param-a": ["param-a-value1", "param-a-value2"],
              "param-subject": "{keycloak.access_token['/sub']}",
              "param-user-name": "{keycloak.access_token['/preferred_username']}",
              "param-other-claims": "{keycloak.access_token['/custom_claim']}"
            }
          }
        }
      }
    ]
  }
```

== Static claims

.keycloak.json
```json
"policy-enforcer": {
    "paths": [
      {
        "path": "/protected/resource",
        "claim-information-point": {
          "claims": {
            "claim-from-static-value": "static value",
            "claim-from-multiple-static-value": ["static", "value"],
          }
        }
      }
    ]
  }
```

== Claim information provider SPI

The Claim Information Provider SPI can be used by developers to support different claim information points in case none of the
built-ins providers are enough to address their requirements.

For example, to implement a new CIP provider you need to implement `org.keycloak.adapters.authorization.ClaimInformationPointProviderFactory`
and `ClaimInformationPointProvider` and also provide the file `META-INF/services/org.keycloak.adapters.authorization.ClaimInformationPointProviderFactory`
in your application`s classpath.

Example of `org.keycloak.adapters.authorization.ClaimInformationPointProviderFactory`:

```java
public class MyClaimInformationPointProviderFactory implements ClaimInformationPointProviderFactory<MyClaimInformationPointProvider> {

    @Override
    public String getName() {
        return "my-claims";
    }

    @Override
    public void init(PolicyEnforcer policyEnforcer) {

    }

    @Override
    public MyClaimInformationPointProvider create(Map<String, Object> config) {
        return new MyClaimInformationPointProvider(config);
    }
}
```

Every CIP provider must be associated with a name, as defined above in the `MyClaimInformationPointProviderFactory.getName` method. The name
will be used to map the configuration from the `claim-information-point` section in the `policy-enforcer` configuration to the implementation.

When processing requests, the policy enforcer will call the MyClaimInformationPointProviderFactory.create method in order to obtain an
instance of MyClaimInformationPointProvider. When called, any configuration defined for this particular CIP provider
(via claim-information-point) is passed as a map.

Example of `ClaimInformationPointProvider`:

```java
public class MyClaimInformationPointProvider implements ClaimInformationPointProvider {

    private final Map<String, Object> config;

    public MyClaimInformationPointProvider(Map<String, Object> config) {
        this.config = config;
    }

    @Override
    public Map<String, List<String>> resolve(HttpFacade httpFacade) {
        Map<String, List<String>> claims = new HashMap<>();

        // put whatever claim you want into the map

        return claims;
    }
}
```
