import { _PdfNativeAlgorithmIdentifier } from './pdf-accumulator';
import { _ISigner } from './pdf-interfaces';
/**
 * Provides an internal RSA‑based message‑digest signer that computes a hash,
 * DER‑encodes the DigestInfo, and produces an RSA signature using PKCS#1 padding.
 *
 * @private
 */
export declare class _PdfRmdSigner implements _ISigner {
    private _digest;
    private _output;
    private _input;
    private _isSigning;
    private _ronCipherEngine;
    private _id;
    private _map;
    /**
     * Contains the requested digest algorithm name (e.g., "sha256").
     *
     * @private
     */
    _algorithmName: string;
    constructor(digest: string);
    private _getMap;
    /**
     * Populates the internal digest‑to‑OID map.
     *
     * @private
     * @returns {void} This method does not return a value.
     */
    _initializeMap(): void;
    /**
     * Selects and returns the internal digest implementation for the given algorithm name.
     *
     * @private
     * @param {string} digest The requested digest algorithm (e.g., "sha256").
     * @returns {any} The digest implementation instance corresponding to the algorithm.
     */
    _getDigest(digest: string): any;
    /**
     * Resolves the AlgorithmIdentifier for the given digest by looking up its OID.
     *
     * @private
     * @param {string} digest The requested digest algorithm (normalized case-insensitive).
     * @returns {_PdfNativeAlgorithmIdentifier} The AlgorithmIdentifier for the digest.
     * @throws {Error} If the digest is unsupported.
     */
    _getAlgorithmIdentifier(digest: string): _PdfNativeAlgorithmIdentifier;
    /**
     * Initializes the signer for signing or verification and prepares the RSA engine.
     *
     * @private
     * @param {boolean} isSigning Specifies whether to initialize for signature generation (true) or verification (false).
     * @param {any} parameters The RSA key parameters to use.
     * @returns {void} This method does not return a value.
     * @throws {Error} If a private key is missing for signing, or a public key is expected for verification.
     */
    _initialize(isSigning: boolean, parameters: any): void;
    /**
     * Feeds a segment of bytes into the ongoing digest computation.
     *
     * @private
     * @param {Uint8Array} input The source buffer containing data.
     * @param {number} inOff The start index within the buffer.
     * @param {number} length The number of bytes to read.
     * @returns {void} This method does not return a value.
     */
    _blockUpdate(input: Uint8Array, inOff: number, length: number): void;
    /**
     * Finalizes the digest, DER‑encodes the DigestInfo, and produces the RSA signature.
     *
     * @private
     * @returns {Uint8Array | null} The generated signature, or null if no hash output is available.
     * @throws {Error} If the signer is not initialized for signing.
     */
    _generateSignature(): Uint8Array | null;
    /**
     * Builds the DER‑encoded DigestInfo structure for the given hash value.
     *
     * @private
     * @param {Uint8Array} hash The raw digest bytes to wrap in DigestInfo.
     * @returns {Uint8Array} The DER‑encoded DigestInfo; may return the hash directly if no identifier is set.
     */
    _derEncode(hash: Uint8Array): Uint8Array;
    /**
     * Resets the internal accumulators and restarts chunked hashing.
     *
     * @private
     * @returns {void} This method does not return a value.
     */
    _reset(): void;
    /**
     * Updates the digest with a single byte value.
     *
     * @private
     * @param {number} input The byte value to add.
     * @returns {void} This method does not return a value.
     */
    _update(input: number): void;
    /**
     * Compares two byte arrays in constant order to determine equality.
     *
     * @private
     * @param {Uint8Array} a The first byte array.
     * @param {Uint8Array} b The second byte array.
     * @returns {boolean} True if the arrays are equal in length and content; otherwise, false.
     */
    _compareArrays(a: Uint8Array, b: Uint8Array): boolean;
}