/**
 * Config File Storage Backend
 *
 * Stores credentials in encrypted JSON file at:
 * ~/.config/ai-changelog/credentials.json
 *
 * Features:
 * - AES-256-GCM encryption
 * - Device-specific key derivation
 * - Metadata storage (auth type, created date, etc.)
 */
import { BaseStorage } from './base-storage.js';
interface EncryptedPayload {
    encrypted: string;
    salt: string;
    iv: string;
    tag: string;
}
interface DecryptedCredential {
    value: string;
    metadata?: Record<string, any>;
}
export declare class ConfigStorage extends BaseStorage {
    [key: string]: any;
    constructor(options?: Record<string, any>);
    /**
     * Ensure config directory exists
     * @private
     */
    _ensureConfigDir(): void;
    /**
     * Get or create master key
     * @private
     * @returns {Buffer}
     */
    _getMasterKey(): any;
    /**
     * Derive encryption key from master key and salt
     * @private
     * @param {Buffer} salt - Salt for key derivation
     * @returns {Buffer}
     */
    _deriveKey(salt: any): NonSharedBuffer;
    /**
     * Encrypt data
     * @private
     * @param {string} data - Data to encrypt
     * @returns {Object} { encrypted: string, salt: string, iv: string, tag: string }
     */
    _encrypt(data: any): {
        encrypted: string;
        salt: string;
        iv: string;
        tag: string;
    };
    /**
     * Decrypt data
     * @private
     * @param {Object} encryptedData - { encrypted, salt, iv, tag }
     * @returns {string}
     */
    _decrypt(encryptedData: EncryptedPayload): string;
    /**
     * Load credentials from file
     * @private
     * @returns {Object}
     */
    _loadCredentials(): Record<string, DecryptedCredential>;
    /**
     * Save credentials to file
     * @private
     * @param {Object} credentials - Credentials object
     */
    _saveCredentials(credentials: Record<string, DecryptedCredential>): void;
    /**
     * Get credential for a provider
     * @param {string} provider - Provider name
     * @returns {Promise<string|null>}
     */
    get(provider: any): Promise<string | null>;
    /**
     * Set credential for a provider
     * @param {string} provider - Provider name
     * @param {string} credential - Credential value
     * @param {Object} metadata - Additional metadata
     * @returns {Promise<void>}
     */
    set(provider: any, credential: any, metadata?: Record<string, any>): Promise<void>;
    /**
     * Delete credential for a provider
     * @param {string} provider - Provider name
     * @returns {Promise<boolean>}
     */
    delete(provider: any): Promise<boolean>;
    /**
     * List all providers with credentials
     * @returns {Promise<string[]>}
     */
    list(): Promise<string[]>;
    /**
     * Get metadata for a credential
     * @param {string} provider - Provider name
     * @returns {Promise<Object|null>}
     */
    getMetadata(provider: any): Promise<Record<string, any> | null>;
    /**
     * Check if storage is available
     * @returns {Promise<boolean>}
     */
    isAvailable(): Promise<boolean>;
    /**
     * Get storage type identifier
     * @returns {string}
     */
    getType(): string;
    /**
     * Get human-readable storage name
     * @returns {string}
     */
    getName(): string;
    /**
     * Get priority for this storage type
     * @returns {number}
     */
    getPriority(): number;
    /**
     * Get config file path
     * @returns {string}
     */
    getConfigPath(): any;
}
export default ConfigStorage;