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# Content Security Policy Interceptor

## Description

Interceptor that implements Content Security Policy on incoming requests.

Content Security Policy (CSP) is an added layer of security that helps to detect and mitigate certain types of attacks, including Cross-Site Scripting (XSS) and data injection attacks. These attacks are used for everything from data theft, to site defacement, to malware distribution.

CSP can work in two modes, either enforce or report. In the report mode the `Content-Security-Policy-Report-Only` header is sent and `Content-Security-Policy` header is used when using the enforce mode.

CSP is now supported by all major browsers. More information about CSP.

## Parameters

- `enforcingMode` (default `false`) - When set to “true”, the enforce mode has been enabled, and the provided policy is going to be enforced.
- `reportUri` - an uri under, which the violations have to be reported.

## Action aware

Since Struts 6.2.0 it is possible to configure the CSP interceptor by providing the an instance of `CspSettings` interface. Please use `CspSettingsAware` interface and implement the `getCspSettings()` method to steer the policy per action.

    public class MyAction implements CspSettingsAware {

        public String execute() {
            return "success";
        }

        public CspSetting getCspSettings() {
          ...
        }
    }

## Examples

    <action  name="someAction" class="com.examples.SomeAction">
        <interceptor-ref name="defaultStack">
            <param name="csp.enforcingMode">true</param>
            <param name="csp.reportUri">/csp-report.action</param>
        </interceptor-ref>
        <result name="success">good_result.ftl</result>
    </action>