import { _PdfNativeAccumulatorSink, _PdfNativeHashInput } from '../digital-signature/signature/pdf-accumulator';
import { _Word64 } from '../encryptor';
/**
 * SHA-512 hash implementation used internally for PDF cryptography.
 *
 * @private
 */
export declare class _Sha512 {
    /**
     * Create a chunked conversion sink for incremental hashing.
     *
     * @private
     * @param {_PdfNativeAccumulatorSink} outputSink that will receive the hash output.
     * @returns {_PdfNativeHashInput} for feeding chunks.
     */
    _startChunkedConversion(outputSink: _PdfNativeAccumulatorSink): _PdfNativeHashInput;
    /**
     * SHA-512 constant round values.
     *
     * @private
     */
    _k: Array<_Word64>;
    /**
     * Upper-case sigma function used in SHA-512 compression.
     *
     * @private
     * @param {_Word64} result `_Word64` to receive the result.
     * @param {_Word64} x `_Word64` value.
     * @param {_Word64} buffer `_Word64` buffer.
     * @returns {void} nothing.
     */
    _sigma(result: _Word64, x: _Word64, buffer: _Word64): void;
    /**
     * Upper-case sigma prime function used in SHA-512 compression.
     *
     * @private
     * @param {_Word64} result `_Word64` to receive the result.
     * @param {_Word64} x `_Word64` value.
     * @param {_Word64} buffer `_Word64` buffer.
     * @returns {void} nothing.
     */
    _sigmaPrime(result: _Word64, x: _Word64, buffer: _Word64): void;
    /**
     * Lower-case sigma function used in message schedule for SHA-512.
     *
     * @private
     * @param {_Word64} result to receive the result.
     * @param {_Word64} x  value.
     * @param {_Word64} buffer  buffer.
     * @returns {void} nothing.
     */
    _littleSigma(result: _Word64, x: _Word64, buffer: _Word64): void;
    /**
     * Lower-case sigma prime function used in message schedule for SHA-512.
     *
     * @private
     * @param {_Word64} result `_Word64` to receive the result.
     * @param {_Word64} x `_Word64` value.
     * @param {_Word64} buffer `_Word64` buffer.
     * @returns {void} nothing.
     */
    _littleSigmaPrime(result: _Word64, x: _Word64, buffer: _Word64): void;
    /**
     * Compute the SHA-512 (or SHA-384 when `isMode384` is true) digest for a slice of bytes.
     *
     * @private
     * @param {Uint8Array} data to hash.
     * @param {number} offset into `data`.
     * @param {number} length bytes to hash.
     * @param {boolean} isMode384 true, produce SHA-384 digest.
     * @returns {Uint8Array} The digest as a `Uint8Array`.
     */
    _hash(data: Uint8Array, offset: number, length: number, isMode384?: boolean): Uint8Array;
}
/**
 * SHA-384 convenience wrapper using the SHA-512 implementation.
 *
 * @private
 */
export declare class _Sha384 {
    /**
     * Create a chunked conversion sink for incremental hashing.
     *
     * @private
     * @param {_PdfNativeAccumulatorSink} outputSink that will receive the hash output.
     * @returns {_PdfNativeHashInput} for feeding chunks.
     */
    _startChunkedConversion(outputSink: _PdfNativeAccumulatorSink): _PdfNativeHashInput;
    /**
     * Compute the SHA-384 digest for a slice of bytes.
     *
     * @private
     * @param {Uint8Array} data bytes to hash.
     * @param {number}  offset into `data`.
     * @param {number} length of bytes to hash.
     * @returns {Uint8Array} The 48-byte SHA-384 digest as `Uint8Array`.
     */
    _hash(data: Uint8Array, offset: number, length: number): Uint8Array;
}