/**
 *
 * @param length Desired length of the code verifier.
 *
 * **NOTE:** According to the [RFC 7636](https://datatracker.ietf.org/doc/html/rfc7636#section-4.1)
 * A code verifier must be with a length >= 43 and <= 128.
 *
 * @returns An object that contains the generated `codeVerifier` and a method
 * `toCodeChallenge` to generate the code challenge from the `codeVerifier`
 * following the spec of [RFC 7636](https://datatracker.ietf.org/doc/html/rfc7636#section-4.2).
 */
export declare const generateCodeVerifier: (length: number) => {
    value: string;
    method: "S256";
    toCodeChallenge(): string;
};