import { _ISigner } from './pdf-interfaces';
/**
 * Provides internal utilities for mapping algorithm names/OIDs and creating
 * signer instances for supported signature mechanisms.
 *
 * @private
 */
export declare class _PdfSignerUtilities {
    private _algorithms;
    private _objectIdentifiers;
    constructor();
    /**
     * Populates the internal algorithm map with known labels and OIDs that normalize
     * to canonical signer mechanisms (e.g., "SHA-256withRSA").
     *
     * @private
     * @returns {void} This method does not return a value.
     */
    _initializeAlgorithmMappings(): void;
    /**
     * Populates the internal mapping from canonical mechanism names to their
     * associated object identifier structures or OIDs.
     *
     * @private
     * @returns {void} This method does not return a value.
     */
    _initializeObjectIdentifierMappings(): void;
    /**
     * Resolves the requested algorithm label to a canonical mechanism and returns
     * a signer implementation for that mechanism.
     *
     * @private
     * @param {string} algorithm The requested algorithm label (case-insensitive; OIDs and variants supported).
     * @returns {_ISigner} A signer corresponding to the canonical mechanism.
     * @throws {Error} If the signer mechanism is not recognized.
     */
    _getSigner(algorithm: string): _ISigner;
}