import { PdfDict, PdfValue } from '../pdf/objects.js';
/** Decrypts the strings and streams of an encrypted PDF, per indirect object. */
export interface Decryptor {
    /**
     * Decrypt one value with its owning object's number and generation (which seed
     * the per-object key). Recurses into arrays and dictionaries.
     */
    decrypt: (value: PdfValue, objNum: number, gen: number) => PdfValue;
}
/**
 * Build a {@link Decryptor} from the `/Encrypt` dictionary and the file `/ID`
 * (ISO 32000 §7.6.3 / ISO 32000-2 §7.6.4). Derives the file key for the
 * handler's revision — R6/V5 via `/UE` (AES-256), else the legacy MD5 key — and
 * picks the cipher (RC4, AES-128 `/AESV2`, AES-256 `/AESV3`).
 *
 * @param encrypt  The `/Encrypt` dictionary.
 * @param idArray  The trailer `/ID` array (its first element seeds the legacy key).
 * @param password The user password (EP14); the empty string opens permissions-only encryption.
 * @returns A decryptor, or `undefined` for a non-Standard filter, an unencrypting
 *          crypt filter, or a password that fails key validation.
 */
export declare function buildDecryptor(encrypt: PdfDict, idArray: PdfValue | undefined, password?: string): Decryptor | undefined;