/**
 * A set of specific error codes for cryptographic operations.
 */
export type CryptoErrorCode = "UNSUPPORTED_ENVIRONMENT" | "ENCRYPTION_FAILED" | "DECRYPTION_FAILED" | "INVALID_DATA" | "EXPIRED";
/**
 * Custom error class for handling specific cryptographic failures.
 * This allows for robust error handling using `instanceof` or by checking the `code`.
 */
export declare class CryptoError extends Error {
    readonly code: CryptoErrorCode;
    readonly cause?: Error;
    constructor(code: CryptoErrorCode, message: string, cause?: Error);
}
/**
 * Encrypts a plaintext string using AES-256-GCM, embedding a TTL.
 *
 * @param plaintext The string to encrypt.
 * @param secretKey The secret key for key derivation.
 * @param ttl The Time-To-Live in milliseconds. Pass `null` to disable expiration. Defaults to 1 hour.
 * @returns A Promise resolving to a URL-safe, Base64 encoded string containing: expiration + salt + iv + encryptedData.
 * @throws {CryptoError} If the environment is unsupported or encryption fails.
 */
export declare function encryptString(plaintext: string, secretKey: string, options?: {
    ttl?: number | null;
}): Promise<string>;
/**
 * Decrypts a string that was encrypted with encryptString, checking its TTL.
 *
 * @param encryptedDataB64 The Base64 encoded string from encryptString.
 * @param secretKey The *same* secret key used for encryption.
 * @returns A Promise resolving to the original plaintext string.
 * @throws {CryptoError} With codes:
 *   - `EXPIRED`: The data's TTL has passed.
 *   - `INVALID_DATA`: The encrypted payload is malformed or too short.
 *   - `DECRYPTION_FAILED`: The secret key is likely incorrect or the data was tampered with.
 *   - `UNSUPPORTED_ENVIRONMENT`: Web Crypto API is not available.
 */
export declare function decryptString(encryptedDataB64: string, secretKey: string): Promise<string>;
/**
 * Asynchronously calculates a deterministic SHA-256 hash of any JavaScript object.
 *
 * This function handles complex data structures including Maps, Sets, Dates,
 * BigInts, and circular references. It creates a consistent, sorted string
 * representation of the object, ensuring that the same logical object always
 * produces the same hash, regardless of key order or environment.
 *
 * @param obj The object to hash. This can be any serializable JavaScript value.
 * @returns A promise that resolves to a string containing the hexadecimal representation of the SHA-256 hash.
 * @example
 * const obj1 = { b: 2, a: { c: 3, d: new Set([1, 2]) } };
 * const obj2 = { a: { d: new Set([2, 1]), c: 3 }, b: 2 };
 * const hash1 = await hashObject(obj1);
 * const hash2 = await hashObject(obj2);
 * // hash1 will be identical to hash2
 */
export declare function hashObject(obj: any): Promise<string>;