/**
 * Provides internal utilities to map digest names and OIDs, resolve canonical algorithm
 * identifiers, and construct message digest instances for hashing.
 *
 * @private
 */
export declare class _PdfMessageDigestAlgorithms {
    /**
     * Internal canonical name for the SHA 1 digest.
     *
     * @private
     */
    readonly _secureHash1: string;
    /**
     * Internal canonical name for the SHA 256 digest.
     *
     * @private
     */
    readonly _secureHash256: string;
    /**
     * Internal canonical name for the SHA 384 digest.
     *
     * @private
     */
    readonly _secureHash384: string;
    /**
     * Internal canonical name for the SHA 512 digest.
     *
     * @private
     */
    readonly _secureHash512: string;
    private _names;
    private _digests;
    private _algorithms;
    constructor();
    /**
     * Initializes the OID → digest short name map used for reverse lookups.
     *
     * @private
     * @returns {void} This method does not return a value.
     */
    _initializeNameMappings(): void;
    /**
     * Initializes the digest label → OID map, accepting multiple name variants.
     *
     * @private
     * @returns {void} This method does not return a value.
     */
    _initializeDigestMappings(): void;
    /**
     * Initializes the algorithm name/OID → canonical algorithm label map.
     *
     * @private
     * @returns {void} This method does not return a value.
     */
    _initializeAlgorithmMappings(): void;
    /**
     * Resolves the digest short name for the specified OID; returns the input if unknown.
     *
     * @private
     * @param {string} id The OID string to resolve (e.g., "1.3.14.3.2.26").
     * @returns {string} The resolved short name (e.g., "SHA1") or the original id if not mapped.
     */
    _getDigest(id: string): string;
    /**
     * Resolves a digest label to its OID if allowed.
     *
     * @private
     * @param {string} name The digest label to resolve (e.g., "SHA-256", "sha256").
     * @returns {string} The corresponding OID if found; otherwise, undefined or null.
     */
    _getAllowedDigests(name: string): string;
    /**
     * Returns an internal message digest implementation instance for the given algorithm label.
     *
     * @private
     * @param {string} hashAlgorithm The requested hash algorithm label (accepts common variants).
     * @returns {any} The message digest instance (e.g., _Sha256, _Sha1, _Sha384, _Sha512, or RIPEMD160 evaluator).
     * @throws {Error} If the algorithm is invalid or unsupported.
     */
    _getMessageDigest(hashAlgorithm: string): any;
    /**
     * Computes the digest for the given data using the requested algorithm name.
     *
     * @private
     * @param {Uint8Array} data The input data to hash.
     * @param {string} hashAlgorithm The algorithm label to use (e.g., "SHA-256").
     * @returns {Uint8Array} The computed hash bytes.
     */
    _digest(data: Uint8Array, hashAlgorithm: string): Uint8Array;
}