/**
 * Ensure the password meets complexity requirements
 * @param password
 * @returns {boolean|boolean}
 */
export declare function isValidPassword(password: string): boolean;
/**
 * Ensure the cipher is supported by OpenSSL
 * @param cipher
 * @returns {boolean}
 */
export declare function isValidCipherAlgorithm(cipher: string): boolean;
/**
 * Replace a password string with asterisks.
 * Leaves the first and last characters in plain text
 * @param password
 * @returns {string|null}
 */
export declare function getSafePassword(password: string): string | null;
export declare function getBufferLength(keySize: number): number;