import { SecureKeyGeneratorConfig } from "./interface";
/**
 * SecureKeyGenerator generates RSA key pairs for tokens and stores them securely.
 */
export declare class SecureKeyGenerator {
    private readonly SECURE_FILE_PERMISSIONS;
    private readonly KEY_DIRECTORY?;
    private readonly keyPath?;
    private readonly envFileName;
    private readonly modulusLength;
    private readonly logger;
    constructor(config?: SecureKeyGeneratorConfig);
    /**
     * Generates an RSA key pair.
     * @param keyType - Type of key ("access" or "refresh").
     * @returns The generated KeyPair.
     */
    private generateRSAKeyPair;
    /**
     * Generates a secure random passphrase.
     * @returns A hex string representing the passphrase.
     */
    private generateSecurePassphrase;
    /**
     * Validates the generated key pair by signing and verifying a test message.
     * @param publicKey - The public key.
     * @param privateKey - The private key.
     */
    private validateKeyPair;
    /**
     * Creates the directory for storing keys with secure permissions.
     */
    private createSecureKeyDirectory;
    /**
     * Loads existing environment variables from the configured env file.
     * @returns An object containing key/value pairs from the env file.
     */
    private loadExistingEnv;
    /**
     * Writes a file with the specified permissions, with fallback on failure.
     * @param filePath - The path to the file.
     * @param content - The file content.
     * @param mode - The file permission mode.
     */
    private writeFileWithFallback;
    /**
     * Saves the generated token keys to disk and updates the environment file.
     * @param tokenKeys - The generated token key pairs.
     */
    private saveKeys;
    /**
     * Prints security instructions to the console.
     */
    private printSecurityInstructions;
    /**
     * Public method to generate RSA token key pairs.
     */
    generate(): Promise<void>;
}
export default SecureKeyGenerator;