/** \file
 * \brief A cache for session and domain hashes, used for Farbling
 *
 *  \author Copyright (C) 2021  Matus Svancar
 *  \author Copyright (C) 2021  Giorgio Maone
 *
 *  \license SPDX-License-Identifier: GPL-3.0-or-later
 */
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
//

/**
 * Object for generating and caching domain/session hashes
 * getFor method used to get domain hashes from given url
 *
 * \note cached visited domains with related keys are only deleted after end of the session
 */
var Hashes = {
  sessionHash : gen_random64().toString(),
  visitedDomains : {},
  getFor(url){
		let site = getSiteForURL(url);
	  let domainHash = this.visitedDomains[site];
	  if (!domainHash) {
		  let hmac = sha256.hmac.create(this.sessionHash);
		  hmac.update(site);
		  domainHash = hmac.hex();
		  this.visitedDomains[site] = domainHash;
	  }
    return {
      domainHash
    };
  }
};