export declare const sha256: {
    hex: (s: string) => string;
    b64: (k: string, d: string) => string;
    any: (k: string, d: string, e: string) => string;
    hex_hmac: (k: string, d: string) => string;
    b64_hmac: (k: string, d: string) => string;
    any_hmac: (k: string, d: string, e: string) => string;
};