import type { HeaderValue, SecurityHeadersOptions, SecurityHeadersPreset } from "./types";
export type HeaderMap = Record<string, HeaderValue>;
export declare const CACHE_LIMIT = 256;
export declare const DEFAULT_HSTS_MAX_AGE = 31536000;
export declare const DEFAULT_NONCE_STATE_KEY = "cspNonce";
export declare const QUOTED_CSP_KEYWORDS: Set<string>;
export declare const FLAG_CSP_DIRECTIVES: Set<string>;
export declare const SINGLE_VALUE_CSP_DIRECTIVES: Set<string>;
export declare const KNOWN_CSP_DIRECTIVES: Set<string>;
export declare const KNOWN_PERMISSIONS_POLICY_FEATURES: Set<string>;
export declare const DEFAULT_HEADERS: HeaderMap;
export declare const DEFAULT_CSP_DIRECTIVES: Record<string, string[]>;
export declare const SECURITY_PRESETS: Record<SecurityHeadersPreset, SecurityHeadersOptions>;