import { ByteArray } from '../../types.js';
import { PdfEncryptionDictionary } from '../types.js';
import { PdfV4SecurityHandler } from './v4.js';
import { PdfStandardSecurityHandlerOptions } from './base.js';
import { Cipher } from '../../crypto/types.js';
/**
 * V5 security handler implementing AES-256-CBC encryption.
 * This is the most secure encryption method (PDF 2.0).
 *
 * @example
 * ```typescript
 * const handler = new PdfV5SecurityHandler({
 *     password: 'strongPassword123',
 *     ownerPassword: 'adminPassword456'
 * })
 * ```
 */
export declare class PdfV5SecurityHandler extends PdfV4SecurityHandler {
    /** User encrypted file key (UE value). */
    protected userEncryptedFileKey?: ByteArray;
    /** Owner encrypted file key (OE value). */
    protected ownerEncryptedFileKey?: ByteArray;
    /** Permissions entry (Perms value). */
    protected perms?: ByteArray;
    /** Promise resolving to the file encryption key. */
    protected fileKey?: Promise<ByteArray>;
    /**
     * Creates a new V5 security handler with AES-256 encryption.
     *
     * @param options - Configuration options including optional pre-computed keys.
     */
    constructor(options: PdfStandardSecurityHandlerOptions & {
        userEncryptedFileKey?: ByteArray;
        ownerEncryptedFileKey?: ByteArray;
    });
    /**
     * Checks if the handler is ready (has user encrypted file key).
     *
     * @returns True if the handler has the required keys.
     */
    isReady(): boolean;
    /**
     * Initializes encryption keys, either deriving from existing values or generating new ones.
     */
    protected initKeys(): Promise<void>;
    /**
     * Computes the master encryption key.
     *
     * @returns The file encryption key.
     * @throws Error if file key is not initialized.
     */
    protected computeMasterKey(): Promise<ByteArray>;
    /**
     * Builds the Perms entry for the encryption dictionary.
     *
     * @param flags - The permission flags.
     * @param encryptMetadata - Whether metadata is encrypted.
     * @param fileKey - The file encryption key.
     * @returns The encrypted permissions entry.
     */
    private buildPermsEntry;
    /**
     * Gets the encryption key length in bits.
     *
     * @returns 256 for V5 encryption.
     */
    getKeyBits(): number;
    /**
     * Gets an AES-256 cipher.
     *
     * @returns An AES-256 cipher instance.
     */
    protected getCipher(): Promise<Cipher>;
    /**
     * Gets the encryption version number.
     *
     * @returns 5 for AES-256 encryption.
     */
    getVersion(): number;
    /**
     * Gets the encryption revision number.
     *
     * @returns 6 for V5 encryption.
     */
    getRevision(): number;
    /**
     * Writes the encryption dictionary including V5-specific entries.
     *
     * @throws Error if required keys are not computed.
     */
    write(): Promise<void>;
    /**
     * Reads V5-specific encryption parameters from the dictionary.
     *
     * @param encryptionDictionary - The encryption dictionary from the PDF.
     * @throws Error if required entries are missing or invalid.
     */
    readEncryptionDictionary(encryptionDictionary: PdfEncryptionDictionary): void;
    /**
     * Computes the object encryption key (same as master key for V5).
     *
     * @returns The master encryption key.
     */
    computeObjectKey(): Promise<ByteArray>;
    /**
     * Recovers the user password from the owner password.
     * Not supported for AES-256 encryption.
     *
     * @throws Error always, as this operation is not supported for V5.
     */
    recoverUserPassword(ownerPassword?: ByteArray | string): Promise<string>;
}