SdesNegotiator.cpp

/*
 *  Copyright (C) 2009 Savoir-Faire Linux inc.
 *  Author: Pierre-Luc Bacon <pierre-luc.bacon@savoirfairelinux.com>
 *
 *  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, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "SdesNegotiator.h"

#include "Pattern.h"

#include <cstdio>
#include <iostream>
#include <sstream>
#include <algorithm>
#include <stdexcept>

using namespace sfl;

SdesNegotiator::SdesNegotiator (const std::vector<CryptoSuiteDefinition>& localCapabilites,
                                const std::vector<std::string>& remoteAttribute) :
        _remoteAttribute (remoteAttribute),
        _localCapabilities (localCapabilites)
{

}

std::vector<CryptoAttribute *> SdesNegotiator::parse (void)
{
    // The patterns below try to follow
    // the ABNF grammar rules described in
    // RFC4568 section 9.2 with the general
    // syntax :
    //a=crypto:tag 1*WSP crypto-suite 1*WSP key-params *(1*WSP session-param)

    Pattern
    * generalSyntaxPattern,
    * tagPattern,
    * cryptoSuitePattern,
    * keyParamsPattern,
    * sessionParamPattern;

    try {

        // used to match white space (which are used as separator) 
        generalSyntaxPattern = new Pattern ("[\x20\x09]+", "g");

        tagPattern = new Pattern ("^a=crypto:(?P<tag>[0-9]{1,9})");

        cryptoSuitePattern = new Pattern (
            "(?P<cryptoSuite>AES_CM_128_HMAC_SHA1_80|" \
            "AES_CM_128_HMAC_SHA1_32|" \
            "F8_128_HMAC_SHA1_80|" \
            "[A-Za-z0-9_]+)"); // srtp-crypto-suite-ext

        keyParamsPattern = new Pattern (
            "(?P<srtpKeyMethod>inline|[A-Za-z0-9_]+)\\:" \
            "(?P<srtpKeyInfo>[A-Za-z0-9\x2B\x2F\x3D]+)\\|" \
            "2\\^(?P<lifetime>[0-9]+)\\|" \