import { QueryParams } from './QueryParams';
import { RequestSigner } from './RequestSigner';
import { Credentials } from './SignalingClient';
/**
 * Utility class for SigV4 signing requests. The AWS SDK cannot be used for this purpose because it does not have support for WebSocket endpoints.
 */
export declare class SigV4RequestSigner implements RequestSigner {
    private static readonly DEFAULT_ALGORITHM;
    private static readonly DEFAULT_SERVICE;
    private readonly region;
    private readonly credentials;
    private readonly service;
    constructor(region: string, credentials: Credentials, service?: string);
    /**
     * Creates a SigV4 signed WebSocket URL for the given host/endpoint with the given query params.
     *
     * @param endpoint The WebSocket service endpoint including protocol, hostname, and path (if applicable).
     * @param queryParams Query parameters to include in the URL.
     * @param date Date to use for request signing. Defaults to NOW.
     *
     * Implementation note: Query parameters should be in alphabetical order.
     *
     * Note from AWS docs: "When you add the X-Amz-Security-Token parameter to the query string, some services require that you include this parameter in the
     * canonical (signed) request. For other services, you add this parameter at the end, after you calculate the signature. For details, see the API reference
     * documentation for that service." KVS Signaling Service requires that the session token is added to the canonical request.
     *
     * @see https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-query-string-auth.html
     * @see https://gist.github.com/prestomation/24b959e51250a8723b9a5a4f70dcae08
     */
    getSignedURL(endpoint: string, queryParams: QueryParams, date?: Date): Promise<string>;
    /**
     * Utility method for generating the key to use for calculating the signature. This combines together the date string, region, service name, and secret
     * access key.
     *
     * @see https://docs.aws.amazon.com/general/latest/gr/sigv4-calculate-signature.html
     */
    private getSignatureKey;
    /**
     * Utility method for converting a map of headers to a string for signing.
     */
    private static createHeadersString;
    /**
     * Utility method for converting a map of query parameters to a string with the parameter names sorted.
     */
    private static createQueryString;
    /**
     * Gets a datetime string for the given date to use for signing. For example: "20190927T165210Z"
     * @param date
     */
    private static getDateTimeString;
    /**
     * Gets a date string for the given date to use for signing. For example: "20190927"
     * @param date
     */
    private static getDateString;
    private static sha256;
    private static hmac;
    /**
     * Note that this implementation does not work with two-byte characters.
     * However, no inputs into a signed signaling service request should have two-byte characters.
     */
    private static toUint8Array;
    private static toHex;
}