/**
 * @license
 * Copyright 2020 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
import * as EllipticCurves from '../subtle/elliptic_curves';
import { PbEllipticCurveType, PbHashType, PbKeyset, PbKeysetKey, PbPointFormat } from './proto';
/**
 * A type representing the constructor function for a given class. Unlike
 * TypeScript's built-in `new` types, this works with abstract classes. It is
 * used to describe the relationship between a primitive type object and its
 * instances.
 */
export declare type Constructor<T> = Function & {
    prototype: T;
};
/** Like the `instanceof` operator, but works with `Constructor`. */
export declare function isInstanceOf<T>(value: unknown, ctor: Constructor<T>): value is T;
/**
 * Validates the given key and throws SecurityException if it is invalid.
 *
 */
export declare function validateKey(key: PbKeysetKey): void;
/**
 * Validates the given keyset and throws SecurityException if it is invalid.
 *
 */
export declare function validateKeyset(keyset: PbKeyset): void;
/**
 * Either prolong or shrinks the array representing number in BigEndian encoding
 * to have the specified size. As webcrypto API assumes that x, y and d values
 * has exactly the supposed number of bytes, whereas corresponding x, y and
 * keyValue values in proto might either have some leading zeros or the leading
 * zeros might be missing.
 *
 */
export declare function bigEndianNumberToCorrectLength(bigEndianNumber: Uint8Array, sizeInBytes: number): Uint8Array;
export declare function curveTypeProtoToSubtle(curveTypeProto: PbEllipticCurveType): EllipticCurves.CurveType;
export declare function hashTypeProtoToString(hashTypeProto: PbHashType): string;
export declare function pointFormatProtoToSubtle(pointFormatProto: PbPointFormat): EllipticCurves.PointFormatType;