<?php
/**
 * 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; under version 2
 * of the License (non-upgradable).
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2002-2008 (original work) Public Research Centre Henri Tudor & University of Luxembourg (under the project TAO & TAO2);
 *               2008-2010 (update and modification) Deutsche Institut für Internationale Pädagogische Forschung (under the project TAO-TRANSFER);
 *               2009-2012 (update and modification) Public Research Centre Henri Tudor (under the project TAO-SUSTAIN & TAO-DEV);
 *               2013 (update and modification) Open Assessment Technologies SA (under the project TAO-PRODUCT);
 *
 */

/**
 * Oauth Services based on the TAO DataStore implementation
 *
 * @access public
 * @author Joel Bout, <joel@taotesting.com>
 * @package tao

 */
interface common_http_SignatureService
{

    /**
     * Returns the signed version of the request
     *
     * @access public
     * @author Joel Bout, <joel@taotesting.com>
     * @return common_http_Request
     */
    public function sign(common_http_Request $request, common_http_Credentials $credentials);

    /**
     * Validates the signature of the current request
     *
     * @access protected
     * @author Joel Bout, <joel@taotesting.com>
     * @param  common_http_Request request
     * @throws common_Exception exception thrown if validation fails
     */
    public function validate(common_http_Request $request, common_http_Credentials $credentials = null);
}