import { Cipher } from '../../crypto/types.js';
import { ByteArray } from '../../types.js';
import { PdfCryptFilter } from '../crypt-filters/base.js';
import { CryptFilterType, PdfEncryptionAlgorithmType, PdfEncryptionDictionary } from '../types.js';
import { PdfStandardSecurityHandlerOptions } from './base.js';
import { PdfV2SecurityHandler } from './v2.js';
/**
 * V4 security handler implementing AES-128-CBC encryption with crypt filters.
 * Supports different encryption methods for strings, streams, and embedded files (PDF 1.5).
 *
 * @example
 * ```typescript
 * const handler = new PdfV4SecurityHandler({
 *     password: 'user123',
 *     ownerPassword: 'admin456'
 * })
 * handler.setCryptFilter('StmFilter', new AesV2CryptFilter({ authEvent: 'DocOpen' }))
 * ```
 */
export declare class PdfV4SecurityHandler extends PdfV2SecurityHandler {
    /** Map of named crypt filters. */
    protected cryptFilters: Map<string, PdfCryptFilter>;
    /** Mapping of content types to crypt filter names. */
    protected cryptFiltersByType: {
        [key in CryptFilterType]?: string;
    };
    /**
     * Creates a new V4 security handler with AES-128 encryption.
     *
     * @param options - Configuration options for the handler.
     */
    constructor(options: PdfStandardSecurityHandlerOptions);
    /**
     * Gets a crypt filter by name.
     *
     * @param name - The crypt filter name.
     * @returns The crypt filter, or undefined if not found.
     */
    getCryptFilter(name: string): PdfCryptFilter | undefined;
    /**
     * Gets the crypt filter assigned to a content type.
     *
     * @param type - The content type ('string', 'stream', or 'file').
     * @returns The assigned crypt filter, or null if none.
     */
    getCryptFilterByType(type: CryptFilterType): PdfCryptFilter | null;
    /**
     * Assigns a crypt filter to a content type.
     *
     * @param type - The content type.
     * @param name - The crypt filter name.
     */
    setCryptFilterForType(type: CryptFilterType, name: string): void;
    /**
     * Registers a named crypt filter.
     *
     * @param name - The filter name.
     * @param filter - The crypt filter instance.
     */
    setCryptFilter(name: string, filter: PdfCryptFilter): void;
    /**
     * Gets the encryption revision number.
     *
     * @returns 4 for V4 encryption.
     */
    getRevision(): number;
    /**
     * Gets the encryption version number.
     *
     * @returns 4 for crypt filter-based encryption.
     */
    getVersion(): number;
    /**
     * Computes the object-specific encryption key.
     *
     * @param objectNumber - The PDF object number.
     * @param generationNumber - The PDF generation number.
     * @param algorithm - Optional algorithm type for key derivation.
     * @returns The computed object key.
     * @throws Error if object or generation number is invalid.
     */
    computeObjectKey(objectNumber?: number, generationNumber?: number, algorithm?: PdfEncryptionAlgorithmType): Promise<ByteArray>;
    /**
     * Gets an AES-128 cipher for the specified object.
     *
     * @param objectNumber - The PDF object number.
     * @param generationNumber - The PDF generation number.
     * @returns An AES-128 cipher instance.
     */
    protected getCipher(objectNumber?: number, generationNumber?: number): Promise<Cipher>;
    /**
     * Reads encryption parameters and crypt filter definitions from the dictionary.
     *
     * @param encryptionDictionary - The encryption dictionary from the PDF.
     */
    readEncryptionDictionary(encryptionDictionary: PdfEncryptionDictionary): void;
    /**
     * Writes the encryption dictionary including crypt filter definitions.
     */
    write(): Promise<void>;
    /**
     * Encrypts data using the appropriate crypt filter for the content type.
     *
     * @param type - The type of content being encrypted.
     * @param data - The data to encrypt.
     * @param objectNumber - The PDF object number.
     * @param generationNumber - The PDF generation number.
     * @returns The encrypted data.
     */
    encrypt(type: 'string' | 'stream' | 'file', data: ByteArray, objectNumber?: number, generationNumber?: number): Promise<ByteArray>;
    /**
     * Decrypts data using the appropriate crypt filter for the content type.
     *
     * @param type - The type of content being decrypted.
     * @param data - The encrypted data.
     * @param objectNumber - The PDF object number.
     * @param generationNumber - The PDF generation number.
     * @returns The decrypted data.
     */
    decrypt(type: 'string' | 'stream' | 'file', data: ByteArray, objectNumber?: number, generationNumber?: number): Promise<ByteArray>;
}