import { Cipher } from '../../crypto/types.js';
import { ByteArray } from '../../types.js';
import { PdfSecurityHandler } from '../handlers/base.js';
import { PdfCryptFilterDictionary } from '../types.js';
/**
 * Configuration options for creating a crypt filter.
 */
export type CryptFilterOptions = {
    /** Security handler for key derivation and encryption operations. */
    securityHandler?: PdfSecurityHandler;
    /** Crypt filter method: 'None' (identity), 'V2' (RC4), 'AESV2' (AES-128), or 'AESV3' (AES-256). */
    cfm: 'None' | 'V2' | 'AESV2' | 'AESV3';
    /** Event that triggers authentication: 'DocOpen' or 'EFOpen' (embedded file open). */
    authEvent: 'DocOpen' | 'EFOpen';
    /** Key length in bits. */
    length?: number;
};
/**
 * Abstract base class for PDF crypt filters.
 * Crypt filters define how specific types of data (strings, streams, files) are encrypted.
 *
 * @example
 * ```typescript
 * const filter = new AesV2CryptFilter({ authEvent: 'DocOpen' })
 * filter.setSecurityHandler(securityHandler)
 * const encrypted = await filter.encrypt(data, objectNumber, generationNumber)
 * ```
 */
export declare abstract class PdfCryptFilter {
    /** Crypt filter method identifier. */
    cfm: 'None' | 'V2' | 'AESV2' | 'AESV3';
    /** Authentication event trigger. */
    authEvent?: 'DocOpen' | 'EFOpen';
    /** Key length in bits. */
    length: number;
    /** Security handler for cryptographic operations. */
    protected securityHandler?: PdfSecurityHandler;
    /**
     * Creates a new crypt filter with the specified options.
     *
     * @param options - Configuration options for the crypt filter.
     */
    constructor(options: CryptFilterOptions);
    /**
     * Sets the security handler for this crypt filter.
     *
     * @param handler - The security handler to use for key derivation.
     */
    setSecurityHandler(handler: PdfSecurityHandler): void;
    /**
     * Gets the current security handler.
     *
     * @returns The security handler, or undefined if not set.
     */
    getSecurityHandler(): PdfSecurityHandler | undefined;
    /**
     * Gets a cipher instance for encrypting/decrypting data.
     *
     * @param objectNumber - The PDF object number for key derivation.
     * @param generationNumber - The PDF generation number for key derivation.
     * @returns A cipher instance for encryption/decryption operations.
     */
    abstract getCipher(objectNumber?: number, generationNumber?: number): Promise<Cipher>;
    /**
     * Encrypts data using this crypt filter.
     *
     * @param data - The data to encrypt.
     * @param objectNumber - The PDF object number for key derivation.
     * @param generationNumber - The PDF generation number for key derivation.
     * @returns The encrypted data.
     */
    encrypt(data: ByteArray, objectNumber?: number, generationNumber?: number): Promise<ByteArray>;
    /**
     * Decrypts data using this crypt filter.
     *
     * @param data - The data to decrypt.
     * @param objectNumber - The PDF object number for key derivation.
     * @param generationNumber - The PDF generation number for key derivation.
     * @returns The decrypted data.
     */
    decrypt(data: ByteArray, objectNumber?: number, generationNumber?: number): Promise<ByteArray>;
    /**
     * Converts this crypt filter to a PDF dictionary representation.
     *
     * @returns The crypt filter dictionary.
     */
    toDictionary(): PdfCryptFilterDictionary;
}