export declare const ALLOWED_DIRECTIVES: {
    'base-uri': string;
    'block-all-mixed-content': string;
    'child-src': string;
    'connect-src': string;
    'default-src': string;
    'font-src': string;
    'form-action': string;
    'frame-ancestors': string;
    'frame-src': string;
    'img-src': string;
    'manifest-src': string;
    'media-src': string;
    'navigate-to': string;
    'object-src': string;
    'plugin-types': string;
    'prefetch-src': string;
    referrer: string;
    'report-to': string;
    'report-uri': string;
    'require-sri-for': string;
    'require-trusted-types-for': string;
    sandbox: string;
    'script-src': string;
    'script-src-attr': string;
    'script-src-elem': string;
    'style-src': string;
    'style-src-attr': string;
    'style-src-elem': string;
    'trusted-types': string;
    'upgrade-insecure-requests': string;
    webrtc: string;
    'worker-src': string;
};