in add-security-headers/index.js [1:16]
function handler(event) {
var response = event.response;
var headers = response.headers;
// Set HTTP security headers
// Since JavaScript doesn't allow for hyphens in variable names, we use the dict["key"] notation
headers['strict-transport-security'] = { value: 'max-age=63072000; includeSubdomains; preload'};
headers['content-security-policy'] = { value: "default-src 'none'; img-src 'self'; script-src 'self'; style-src 'self'; object-src 'none'; frame-ancestors 'none'"};
headers['x-content-type-options'] = { value: 'nosniff'};
headers['x-frame-options'] = {value: 'DENY'};
headers['x-xss-protection'] = {value: '1; mode=block'};
headers['referrer-policy'] = {value: 'same-origin'};
// Return the response to viewers
return response;
}