include::../description.adoc[]

include::../ask-yourself.adoc[]

include::../recommended.adoc[]

== Sensitive Code Example

In Express.js application the code is sensitive if the https://www.npmjs.com/package/helmet-csp[helmet-csp] or https://www.npmjs.com/package/helmet[helmet] middleware is used without the ``++frameAncestors++`` directive (or if ``++frameAncestors++`` is set to ``++'none'++``):

----
const express = require('express');
const helmet = require('helmet');

let app = express();

app.use(
  helmet.contentSecurityPolicy({
    directives: {
      // other directives
      frameAncestors: ["'none'"] // Sensitive: frameAncestors  is set to none
    } 
  })
);
----

== Compliant Solution

In Express.js application a standard way to implement CSP frame-ancestors directive is the https://www.npmjs.com/package/helmet-csp[helmet-csp] or https://www.npmjs.com/package/helmet[helmet] middleware:

[source,javascript]
----
const express = require('express');
const helmet = require('helmet');

let app = express();

app.use(
  helmet.contentSecurityPolicy({
    directives: {
      // other directives
      frameAncestors: ["'example.com'"] // Compliant
    } 
  })
);
----

include::../see.adoc[]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

include::../message.adoc[]

endif::env-github,rspecator-view[]